#include <bits/stdc++.h>
#pragma optimization_level 3
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
using namespace std;
const long double PI = 3.14159265358979323846;
const long long mod = 1e+9 + 7;
const int INFi = INT_MAX;
const long long INF = (long long)1e+9 + 7;
const int N = 1200300, LOGN = 30, V = N * LOGN;
long long dx4[] = {0, 1, 0, -1}, dy4[] = {1, 0, -1, 0};
int t = 1;
long long a, b, c, ans;
string second;
void MAIN() {
  cin >> a >> b >> c;
  ans = 0;
  ans = max(ans, a / 3 + b / 3 + c / 3);
  if (a > 0 && b > 0 && c > 0)
    ans = max(ans, 1 + (a - 1) / 3 + (b - 1) / 3 + (c - 1) / 3);
  if (a > 1 && b > 1 && c > 1)
    ans = max(ans, 2 + (a - 2) / 3 + (b - 2) / 3 + (c - 2) / 3);
  cout << ans << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed;
  cout << setprecision(10);
  ;
  mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
  ;
  while (t--) {
    MAIN();
  }
}
