#include <bits/stdc++.h>
using namespace std;
long long r, g, b, high = 0;
int main() {
  scanf("%I64d %I64d %I64d", &r, &g, &b);
  high = r / 3 + g / 3 + b / 3 + min(r % 3, min(g % 3, b % 3));
  if (r > 0 && g > 0 && b > 0) {
    if (high < 1 + (r - 1) / 3 + (g - 1) / 3 + (b - 1) / 3 +
                   min((r - 1) % 3, min((g - 1) % 3, (b - 1) % 3))) {
      high = 1 + (r - 1) / 3 + (g - 1) / 3 + (b - 1) / 3 +
             min((r - 1) % 3, min((g - 1) % 3, (b - 1) % 3));
    }
  }
  if (r > 1 && g > 1 && b > 1) {
    if (high < 2 + (r - 2) / 3 + (g - 2) / 3 + (b - 2) / 3 +
                   min((r - 2) % 3, min((g - 2) % 3, (b - 2) % 3))) {
      high = 2 + (r - 2) / 3 + (g - 2) / 3 + (b - 2) / 3 +
             min((r - 2) % 3, min((g - 2) % 3, (b - 2) % 3));
    }
  }
  printf("%d\n", high);
  return 0;
}
