#include <bits/stdc++.h>
using namespace std;
long long inv(long long a, long long b) {
  return 1 < a ? b - inv(b % a, a) * b / a : 1;
}
void solve() {
  long long r, g, b;
  cin >> r >> g >> b;
  if (g < r) swap(g, r);
  if (b < r) swap(b, r);
  if (g > b) swap(g, b);
  long long x = g - r;
  long long cnt = 0, mini = r;
  if (x % 3 == 0)
    cnt += (x / 3);
  else if (x % 3 == 2) {
    cnt += (x / 3);
    if (r > 0) {
      cnt++;
      mini = r - 1;
    }
  } else if (x > 0 and x % 3 == 1) {
    x--;
    cnt += (x / 3);
    mini = min(mini, r + 1);
  }
  x = b - r;
  if (x % 3 == 0)
    cnt += (x / 3);
  else if (x % 3 == 2) {
    cnt += (x / 3);
    if (r > 0) {
      cnt++;
      mini = r - 1;
    }
  } else if (x > 0 and x % 3 == 1) {
    x--;
    cnt += (x / 3);
    mini = min(mini, r + 1);
  }
  cnt += mini;
  cout << cnt;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t = 1;
  while (t--) solve();
  return 0;
}
