#include <bits/stdc++.h>
using namespace std;
int main() {
  long long r, g, b, res1 = 0, res2 = 0, res3 = 0, ans = 0, sum = 0, r1, g1, b1;
  cin >> r >> g >> b;
  r1 = r;
  g1 = g;
  b1 = b;
  res1 += r / 3 + g / 3 + b / 3;
  if (r > 0 && g > 0 && b > 0) {
    r1--;
    g1--;
    b1--;
    res2 = 1;
  }
  if (r > 1 && g > 1 && b > 1) {
    r -= 2;
    g -= 2;
    b -= 2;
    res3 = 2;
  }
  res2 += r1 / 3 + g1 / 3 + b1 / 3;
  res3 += r / 3 + g / 3 + b / 3;
  ans = max(max(res1, res2), res3);
  printf("%lld\n", ans);
  return 0;
}
