#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define MAX_SIZE  1000000000



int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int a,b,c;
    cin >> a >> b >> c;
    a -= b;
    if(b<=0){
        cout << "0" << endl;
        return 0;
    }else{
        cout << a+c << endl;
    }


    return 0;
}

#include <iostream>
using namespace std;

int main(int argc, const char * argv[]) {
    
    int N,A,B;
    cin >> N >> A >> B ;
    cout << ((N+B)-A) << "\n";
    
    
    return 0;
}