Problem:
Score : 100 points

Problem Statement

We have two bottles for holding water.

Bottle 1 can hold up to A milliliters of water, and now it contains B milliliters of water.

Bottle 2 contains C milliliters of water.

We will transfer water from Bottle 2 to Bottle 1 as much as possible.

How much amount of water will remain in Bottle 2?

Constraints

All values in input are integers.

1 \leq B \leq A \leq 20

1 \leq C \leq 20

Input

Input is given from Standard Input in the following format:

A B C

Output

Print the integer representing the amount of water, in milliliters, that will remain in Bottle 2.

Sample Input 1

6 4 3

Sample Output 1

1

We will transfer two milliliters of water from Bottle 2 to Bottle 1, and one milliliter of water will remain in Bottle 2.

Sample Input 2

8 3 9

Sample Output 2

4

Sample Input 3

12 3 7

Sample Output 3

0

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repi(i, s, n) for (int i = (s); i < (n); i++)
#ifdef LOCAL
#define INPUT_FILE                   \
  ifstream in("atcoder-problems/abc136_a.txt"); \
  cin.rdbuf(in.rdbuf());
#define print_vec(v) \
rep(l, v.size()) { cout << v[l] << " "; } \
cout << endl;
#else
#define INPUT_FILE
#define print_vec(v)
#endif
#define CIN_OPTIMIZE \
  cin.tie(0);        \
  ios::sync_with_stdio(false);
typedef pair<int, int> P;
typedef long long ll;
typedef pair<ll, ll> pl;
const int INF = 100100100;
const ll LINF = 1e18+100;
const int MOD = 1e9 + 7;

int main() {
  INPUT_FILE CIN_OPTIMIZE;

  int A, B, C;
  cin >> A >> B >> C;

  int lim = A - B;
  int ans = C - lim;
  cout << (ans > 0 ? ans : 0) << endl;
}