#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>

using namespace std;

#define int long long
#define endl "\n"

const long long INF = (long long)1e18;
const long long MOD = 1'000'000'007; 

string yn(bool f){return f?"Yes":"No";}
string YN(bool f){return f?"YES":"NO";}



signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	int X, Y, Z;
	int ans = 0;
	cin>>X>>Y>>Z;
	
	for(int i = 0; i <= Z; i++){
		ans = max(ans, min(X+i,Y+Z-i));
	}
	
	cout<<ans<<endl;
	
	
	return 0;
}