# This program adds three numbers and displays the sum

print("Enter the first number to add:")
first = input()
print("Enter the second number to add:")
second = input()
print("Enter the third number to add:")
third = input()
print("The sum is " + first + second + third)

"""Buggy adding program

This program adds three user inputted numbers and displays the sum.

Note:
    May not work as expected.
"""


def main():
    print("Enter the first number to add:")
    first = input()
    print("Enter the second number to add:")
    second = input()
    print("Enter the third number to add:")
    third = input()
    print("The sum is " + first + second + third)


if __name__ == '__main__':
    main()

Update P7_buggyAddingProgram.py added docstring and wrapped in main() function