#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  long long r, g, b;
  cin >> r >> g >> b;
  long long ans = 0;
  long long tr, tg, tb;
  for (long long i = 0; i <= min({r, g, b, 2LL}); i++) {
    long long t = i;
    tr = r;
    tg = g;
    tb = b;
    tr -= i;
    tg -= i;
    tb -= i;
    t += (tr / 3 + tg / 3 + tb / 3);
    ans = max(ans, t);
  }
  cout << ans;
}
