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

signed main(){
    //cout << setprecision(12) ;
    ios::sync_with_stdio(false);
	cin.tie(0);
 
    ll x,y,z;
    cin>>x>>y>>z;
    ll ans=z;
    if(z>=x) ans--;
    if(z>=y) ans--;
    cout<<ans<<endl;    
}