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



int main(){
	vector<int> num(3);
	for (int i = 0; i < 3; i++)
	{
		cin >> num[i];
	}
	while (true){
		sort(num.begin(), num.end());
		if (num[0] + 3 > num[2]) break;
		num[0]++;
		num[2] -= 2;
	}
	cout << num[0] << endl;
}