#include <bits/stdc++.h>
using namespace std;
int tot;
int maxn;
void dfs(int r, int g, int b, int now) {
  if (now > maxn) maxn = now;
  if (r - 3 >= 0) dfs(r - 3, g, b, now + 1);
  if (g - 3 >= 0) dfs(r, g - 3, b, now + 1);
  if (b - 3 >= 0) dfs(r, g, b - 3, now + 1);
  if (r >= 1 && g >= 1 && b >= 1) dfs(r - 1, g - 1, b - 1, now + 1);
}
int main() {
  int r, g, b;
  while (scanf("%d%d%d", &r, &g, &b) != EOF) {
    maxn = 0;
    tot = 0;
    if (r > 3) {
      tot += (r - 3) / 3;
      r = ((r - 3) % 3) + 3;
    }
    if (g > 3) {
      tot += (g - 3) / 3;
      g = ((g - 3) % 3) + 3;
    }
    if (b > 3) {
      tot += (b - 3) / 3;
      b = ((b - 3) % 3) + 3;
    }
    dfs(r, g, b, 0);
    printf("%d\n", tot + maxn);
  }
  return 0;
}
