diff --git a/main.py b/main.py
index bf10e71..ae7395c 100644
--- a/main.py
+++ b/main.py
@@ -1,5 +1,35 @@
-def main():
-    print("Hello from custombingo!")
+import click
+import os
+from custom_bingo.card_generator import generate_bingo_cards
+from custom_bingo.spreadsheet_reader import read_spreadsheet
+from custom_bingo.pdf_generator import export_cards_to_pdf
+
+
+@click.command()
+@click.option('--input-file', '-i', required=True, type=click.Path(exists=True),
+              help='Input spreadsheet file (Excel/CSV) with B, I, N, G, O columns')
+@click.option('--output-file', '-o', required=True, type=click.Path(),
+              help='Output PDF file for the BINGO cards')
+@click.option('--number-of-cards', '-n', default=1, type=int,
+              help='Number of BINGO cards to generate (default: 1)')
+def main(input_file, output_file, number_of_cards):
+    """Generate custom BINGO cards from a spreadsheet."""
+    try:
+        # Read the spreadsheet data
+        click.echo(f"Reading data from {input_file}...")
+        data = read_spreadsheet(input_file)
+
+        # Generate the bingo cards
+        click.echo(f"Generating {number_of_cards} BINGO card(s)...")
+        cards = generate_bingo_cards(data, number_of_cards)
+
+        # Export to PDF
+        click.echo(f"Exporting cards to {output_file}...")
+        export_cards_to_pdf(cards, output_file)
+
+        click.echo(f"Successfully generated {number_of_cards} BINGO card(s) in {output_file}")
+    except Exception as e:
+        click.echo(f"Error: {str(e)}", err=True)
 
 
 if __name__ == "__main__":
diff --git a/pyproject.toml b/pyproject.toml
index 91e95c8..5ae933e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,3 +10,13 @@ dependencies = [
     "openpyxl>=3.1.0",
     "click>=8.0.0"
 ]
+
+[project.scripts]
+custombingo = "main:main"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+
+[build-system]
+requires = ["setuptools>=45", "wheel"]
+build-backend = "setuptools.build_meta"
diff --git a/src/custom_bingo/__init__.py b/src/custom_bingo/__init__.py
new file mode 100644
index 0000000..f745ded
--- /dev/null
+++ b/src/custom_bingo/__init__.py
@@ -0,0 +1 @@
+# CustomBingo package
\ No newline at end of file
diff --git a/src/custom_bingo/card_generator.py b/src/custom_bingo/card_generator.py
new file mode 100644
index 0000000..bece7bb
--- /dev/null
+++ b/src/custom_bingo/card_generator.py
@@ -0,0 +1,63 @@
+import random
+from typing import Dict, List, Tuple
+
+
+def generate_single_card(data: Dict[str, List[str]]) -> List[List[str]]:
+    """
+    Generate a single BINGO card from the provided data.
+    
+    Args:
+        data: Dictionary with keys 'B', 'I', 'N', 'G', 'O' and values as lists of strings
+        
+    Returns:
+        5x5 matrix representing a BINGO card (list of lists)
+    """
+    card = []
+    
+    # Column B: numbers 1-15
+    b_values = random.sample(data['B'], min(len(data['B']), 5))
+    card.append(b_values + [''] * max(0, 5 - len(b_values)))
+    
+    # Column I: numbers 16-30
+    i_values = random.sample(data['I'], min(len(data['I']), 5))
+    card.append(i_values + [''] * max(0, 5 - len(i_values)))
+    
+    # Column N: numbers 31-45 (with free space in middle)
+    n_values = random.sample(data['N'], min(len(data['N']), 5))
+    # Insert empty string (free space) at position 2 (middle of column)
+    if len(n_values) >= 3:
+        n_values.insert(2, "FREE")
+    else:
+        n_values.append("FREE")
+    card.append(n_values + [''] * max(0, 5 - len(n_values)))
+    
+    # Column G: numbers 46-60
+    g_values = random.sample(data['G'], min(len(data['G']), 5))
+    card.append(g_values + [''] * max(0, 5 - len(g_values)))
+    
+    # Column O: numbers 61-75
+    o_values = random.sample(data['O'], min(len(data['O']), 5))
+    card.append(o_values + [''] * max(0, 5 - len(o_values)))
+    
+    # Transpose to get rows instead of columns
+    transposed_card = [[card[col][row] for col in range(5)] for row in range(5)]
+    
+    return transposed_card
+
+
+def generate_bingo_cards(data: Dict[str, List[str]], number_of_cards: int) -> List[List[List[str]]]:
+    """
+    Generate multiple BINGO cards from the provided data.
+    
+    Args:
+        data: Dictionary with keys 'B', 'I', 'N', 'G', 'O' and values as lists of strings
+        number_of_cards: Number of cards to generate
+        
+    Returns:
+        List of 5x5 matrices representing BINGO cards
+    """
+    cards = []
+    for _ in range(number_of_cards):
+        card = generate_single_card(data)
+        cards.append(card)
+    return cards
\ No newline at end of file
diff --git a/src/custom_bingo/pdf_generator.py b/src/custom_bingo/pdf_generator.py
new file mode 100644
index 0000000..7476cd6
--- /dev/null
+++ b/src/custom_bingo/pdf_generator.py
@@ -0,0 +1,131 @@
+from reportlab.lib.pagesizes import letter, A4
+from reportlab.pdfgen import canvas
+from reportlab.lib.units import inch
+from reportlab.pdfbase import pdfmetrics
+from reportlab.pdfbase.ttfonts import TTFont
+from typing import List
+import math
+
+
+def calculate_font_size(text: str, available_width: float, available_height: float, max_font_size: int = 24) -> int:
+    """
+    Calculate the largest font size that allows the text to fit in the given space.
+    
+    Args:
+        text: Text to fit
+        available_width: Available width in points
+        available_height: Available height in points
+        max_font_size: Maximum font size to consider
+        
+    Returns:
+        Font size that allows the text to fit in the space
+    """
+    if not text:
+        return max_font_size
+    
+    # Start with the maximum font size and decrease until text fits
+    for font_size in range(max_font_size, 0, -1):
+        # Estimate text dimensions (this is a rough approximation)
+        # For more accuracy, we'd need to use the actual font metrics
+        text_width = len(text) * font_size * 0.6  # rough character width estimate
+        text_height = font_size
+        
+        if text_width <= available_width and text_height <= available_height:
+            return font_size
+    
+    return 1  # smallest possible font size
+
+
+def draw_centered_text(c: canvas.Canvas, text: str, x: float, y: float, width: float, height: float, max_font_size: int = 24):
+    """
+    Draw text centered in a given rectangle with the largest possible font size.
+    
+    Args:
+        c: ReportLab canvas
+        text: Text to draw
+        x: X coordinate of bottom-left of rectangle
+        y: Y coordinate of bottom-left of rectangle
+        width: Width of rectangle
+        height: Height of rectangle
+        max_font_size: Maximum font size to use
+    """
+    if not text:
+        return
+        
+    font_size = calculate_font_size(text, width, height, max_font_size)
+    c.setFont("Helvetica", font_size)
+    
+    # Calculate the text dimensions
+    text_width = c.stringWidth(text, "Helvetica", font_size)
+    text_height = font_size
+    
+    # Calculate centered position
+    centered_x = x + (width - text_width) / 2
+    # Vertically center the text
+    # Using font_size * 0.8 as an approximation of text height
+    centered_y = y + (height - text_height * 0.8) / 2 + text_height * 0.2
+    
+    c.drawString(centered_x, centered_y, text)
+
+
+def export_cards_to_pdf(cards: List[List[List[str]]], output_file: str):
+    """
+    Export the generated BINGO cards to a PDF file.
+    
+    Args:
+        cards: List of 5x5 matrices representing BINGO cards
+        output_file: Path for the output PDF file
+    """
+    # Create a new PDF document
+    c = canvas.Canvas(output_file, pagesize=letter)
+    width, height = letter
+    
+    # Define card dimensions
+    margin = 1 * inch
+    card_width = (width - 2 * margin) * 0.8  # Make card 80% of page width
+    card_height = card_width  # Keep card square
+    cell_width = card_width / 5
+    cell_height = card_height / 5
+    
+    # Starting position for the first card (centered horizontally)
+    start_x = (width - card_width) / 2
+    start_y = height - margin - card_height
+    
+    for idx, card in enumerate(cards):
+        # Add a new page for each card after the first
+        if idx > 0:
+            c.showPage()
+            start_y = height - margin - card_height
+        
+        # Draw title
+        c.setFont("Helvetica", 24)
+        title_width = c.stringWidth("BINGO", "Helvetica", 24)
+        c.drawString((width - title_width) / 2, height - margin + 0.5 * inch, "BINGO")
+        
+        # Draw the card grid
+        for row in range(5):
+            for col in range(5):
+                # Calculate the position of this cell
+                cell_x = start_x + col * cell_width
+                cell_y = start_y + (4 - row) * cell_height  # Flip Y-axis so row 0 is at bottom
+                
+                # Draw rectangle for cell
+                c.rect(cell_x, cell_y, cell_width, cell_height)
+                
+                # Get the text for this cell
+                cell_text = card[row][col]
+                
+                # Draw the text centered in the cell
+                draw_centered_text(c, cell_text, cell_x, cell_y, cell_width, cell_height)
+        
+        # Draw column headers (B, I, N, G, O)
+        headers = ['B', 'I', 'N', 'G', 'O']
+        for col, header in enumerate(headers):
+            cell_x = start_x + col * cell_width
+            cell_y = start_y + 5 * cell_height  # Above the grid
+            
+            # Draw header cell (no border, just text)
+            draw_centered_text(c, header, cell_x, cell_y, cell_width, cell_height, max_font_size=18)
+    
+    # Save the PDF
+    c.save()
\ No newline at end of file
diff --git a/src/custom_bingo/spreadsheet_reader.py b/src/custom_bingo/spreadsheet_reader.py
new file mode 100644
index 0000000..9fbb07c
--- /dev/null
+++ b/src/custom_bingo/spreadsheet_reader.py
@@ -0,0 +1,44 @@
+import pandas as pd
+from typing import Dict, List
+
+
+def read_spreadsheet(file_path: str) -> Dict[str, List[str]]:
+    """
+    Read a spreadsheet file and return the data organized by BINGO columns.
+    
+    Args:
+        file_path: Path to the Excel or CSV file
+        
+    Returns:
+        Dictionary with keys 'B', 'I', 'N', 'G', 'O' and values as lists of strings
+    """
+    # Determine file type and read accordingly
+    if file_path.lower().endswith('.csv'):
+        df = pd.read_csv(file_path)
+    elif file_path.lower().endswith(('.xlsx', '.xls')):
+        df = pd.read_excel(file_path)
+    else:
+        raise ValueError("Unsupported file format. Please use CSV or Excel files.")
+    
+    # Validate that the dataframe has exactly 5 columns
+    if len(df.columns) != 5:
+        raise ValueError(f"Spreadsheet must have exactly 5 columns, but found {len(df.columns)}")
+    
+    # Assign column names if they're not already named B, I, N, G, O
+    if not all(col in ['B', 'I', 'N', 'G', 'O'] for col in df.columns):
+        df.columns = ['B', 'I', 'N', 'G', 'O']
+    else:
+        # Ensure the order is B, I, N, G, O
+        df = df[['B', 'I', 'N', 'G', 'O']]
+    
+    # Convert to dictionary of lists
+    data = {}
+    for col in ['B', 'I', 'N', 'G', 'O']:
+        # Drop NaN values and convert to list of strings
+        data[col] = df[col].dropna().astype(str).tolist()
+        
+        # Check for empty columns
+        if len(data[col]) == 0:
+            raise ValueError(f"Column {col} is empty. Each column must contain at least one value.")
+    
+    return data
\ No newline at end of file