#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() { 
  ios::sync_with_stdio(false); cin.tie(0);
  long long x, y, z;
  cin >> x >> y >> z;
  z -= (x <= z);
  z -= (y <= z);
  cout << z << endl;
  return 0;
}