#include <bits/stdc++.h>
using namespace std;
bool good(int r, int g, int b) {
  return (r % 3 == 2 && g % 3 == 2 && b >= 3 && b % 3 == 0);
}
int func(int r, int g, int b) {
  int x = r / 3 + g / 3 + b / 3 + min(r % 3, min(g % 3, b % 3));
  if (good(r, g, b))
    ++x;
  else if (good(r, b, g))
    ++x;
  else if (good(b, g, r))
    ++x;
  return x;
}
int main() {
  int r, g, b;
  scanf("%d %d %d", &r, &g, &b);
  printf("%d\n", func(r, g, b));
  return 0;
}
