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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <cstring>
#include <cmath>
#include <iomanip>
#include <cassert>

#define DEBUG 0
#define fi first
#define se second
#define pb push_back
#define INF 1000000000
#define fore(i,a,b) for (int i = (a), _b = (b); i < (_b); ++i)
#define fort(i,a,b) for (int i = (a), _b = (b); i <= (_b); ++i)
#define ford(i,a,b) for (int i = (a), _b = (b); i >= (_b); --i)

using namespace std;

typedef long long LL;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef vector<int> vi;
typedef vector<vi> vvi;

int main() {
    if (DEBUG) {
        freopen("CP.inp", "r", stdin);
        //freopen("CP.out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(0);
    int a, b, c; cin >> a >> b >> c;
    cout << max(0, c - a + b) << '\n';
    return 0;
}