b.cpp

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
template <typename T1, typename T2>
ostream &operator <<(ostream &os, pair<T1, T2> p){os << p.first << " " << p.second; return os;}
template <typename T>
ostream &operator <<(ostream &os, vector<T> &v){for(T i : v)os << i << ", "; return os;}
template <typename T>
ostream &operator <<(ostream &os, set<T> s){for(T i : s) os << i << ", "; return os;}
template <typename T1, typename T2>
ostream &operator <<(ostream &os, map<T1, T2> m){for(pair<T1, T2> i : m) os << i << endl; return os;}

int main(){
    int r, g, b; cin >> r >> g >> b;
    int m = min(r, min(g, b));
    int ans = 0;
    for(int i = 0; i <= min(3, m); i++){
        ans = max(ans, i + (r - i) / 3 + (g - i) / 3 + (b - i) / 3);
    }
    cout << ans << endl;
    return 0;
}