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 Ruby (2.3.3) (judge verdict: Runtime Error)

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define ALL(a) a.begin(), a.end()
ll dx[4] = { 0, 1, 0, -1 };
ll dy[4] = { 1, 0, -1, 0 };
const ll INF = 1e14;
const ll MOD = 1e9 + 7;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    // input
    int a, b, c;
    cin >> a >> b >> c;
    // output
    cout << max(0, b + c - a) << endl;
    return 0;
}