#include <bits/stdc++.h>
using namespace std;
int x, y, z;
inline int F(int a, int b, int c) { return a / 3 + b / 3 + c / 3; }
int main() {
  int a, b, c, _min;
  scanf("%d %d %d", &a, &b, &c);
  _min = ((a) < (((b) < (c) ? (b) : (c))) ? (a) : (((b) < (c) ? (b) : (c))));
  x = F(a, b, c);
  if (_min >= 1) y = F(a - 1, b - 1, c - 1) + 1;
  if (_min >= 2) z = F(a - 2, b - 2, c - 2) + 2;
  printf("%d\n", max(x, max(y, z)));
  return 0;
}
