#include <bits/stdc++.h>
using namespace std;
int r, g, b;
int main() {
  while (scanf("%d%d%d", &r, &g, &b) != EOF) {
    int ans = min(min(r, g), b);
    if (ans == 0) {
      printf("%d\n", r / 3 + g / 3 + b / 3);
      continue;
    }
    r -= ans, g -= ans, b -= ans;
    ans += r / 3 + g / 3 + b / 3;
    if (r % 3 + g % 3 + b % 3 == 4) ans++;
    printf("%d\n", ans);
  }
  return 0;
}
