import java.util.*;

public class Main {

    long INF = Long.MAX_VALUE;
    long[] dp;
    long n;
    long S;

    public static void main(String[] args) {
        new Main().solve();
    }

    void solve() {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();
        int AB = A-B;
        C -= AB;
        if(C<0){
            C =0;
        } 
        System.out.println(C);
    }

    int gcd(int m, int n) {
        if (m < n) {
            return gcd(n, m);
        }
        if (n == 0) {
            return m;
        }
        return gcd(n, m % n);
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz