A, B, C = list(map(int, input().split()))

if C > (A - B): print((C - (A - B)))

else: print((0))
import sys



def solve():

    input = sys.stdin.readline

    A, B, C = list(map(int, input().split()))

    print((max(0, C - A + B)))



    return 0



if __name__ == "__main__":

    solve()
A, B, C = list(map(int, input().split()))
if C > (A - B):
    print((C - (A - B)))
else:
    print((0))

import sys


def solve():
    input = sys.stdin.readline
    A, B, C = list(map(int, input().split()))
    print((max(0, C - A + B)))
    return 0


if __name__ == "__main__":
    solve()

-A, B, C = list(map(int, input().split())) -if C > (A - B): -    print((C - (A - B))) -else: -    print((0)) +import sys + + +def solve(): +    input = sys.stdin.readline +    A, B, C = list(map(int, input().split())) +    print((max(0, C - A + B))) +    return 0 + + +if __name__ == "__main__": +    solve()