human
3 user input if else.
assistant
Here is a Python function to 3 user input if else, it would be a Python Function

import math

def _if_else(a, b, c):
    """
    A function for 3 user input if else

    :type a: number
    :param a: The first number to check

    :type b: number
    :param b: The second number to check

    :type c: number
    :param c: The third number to check
    """

    if a > b and a > c:
        return a
    elif b > a and b > c:
        return b
    elif c > a and c > b:
        return c
    else:
        return 0

# Enter the numbers
a = 12
b = 15
c = 18

# Calling the function
print((_if_else(a, b, c)))

#Example Output
# 18

#Remember to inspect code for bugs.