#include <bits/stdc++.h>
using namespace std;
int r[3], i, ans;
int main() {
  for (i = 0; i < 3; ++i) scanf("%d", r + i);
  sort(r, r + 3);
  for (i = 0; i <= min(r[0], 2); ++i)
    ans = max(ans, i + (r[0] - i) / 3 + (r[1] - i) / 3 + (r[2] - i) / 3);
  printf("%d\n", ans);
  return 0;
}
