sum of two

n1 = int(input())
n2 = int(input())
magic_num = int(input())
combination = 0

for first in range(n1, n2 + 1):
    for second in range(n1, n2 + 1):
        combination += 1
        if first + second == magic_num:
            break
    if first + second == magic_num:
        break

if first + second != magic_num:
    print(f'{combination} combinations - neither equals {magic_num}')
else:
    print(f'Combination N:{combination} ({n1} + {n2} = {magic_num})')