#!/usr/bin/env python3
"""Auto-generated by AGI Loop cycle #1255
Task: ‘$$

</think>

Write a Python function that takes a list of integers and returns the sum of all even numbers in the list.
Generated: 2026-02-13T01:58:26.982594
"""

def sum_even_numbers(numbers):
    return sum(num for num in numbers if num % 2 == 0)

if __name__ == '__main__':
    test_data = [1, 2, 3, 4, 5, 6]
    result = sum_even_numbers(test_data)
    print(f"Sum of even numbers: {result}")