#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <climits>
#include <iomanip>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
int main(){
    ll a,b,c;
    cin >> a >> b >> c;
    ll res = c;
    if(c >= a)res--;
    if(c >= b)res--;
    cout << res << endl;
}