#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    function<int(vector<int>)> dfs = [&](vector<int> A) -> int {
        int res = *min_element(A.begin(), A.end());
        rep(i,3) A[i] -= res;
        int argMax = max_element(A.begin(), A.end()) - A.begin();
        int argMin = min_element(A.begin(), A.end()) - A.begin();
        if(argMax == argMin || A[argMax] <= 1) return res;
        else {
            A[argMax] -= 2;
            A[argMin] += 1;
            return res + dfs(A);
        }
    };

    vector<int> A(3); rep(i,3) cin >> A[i];
    cout << dfs(A) << endl;
}