Add and subtract

num_1 = int(input())
num_2 = int(input())
num_3 = int(input())

def add(a, b):
    return a + b

def subtract(r, c):
    return r - c

def add_and_subtract(x, y, z):
    return subtract(add(x, y), z)

print(add_and_subtract(num_1, num_2, num_3))