#include <bits/stdc++.h>

inline long nextInt(void) {
  long temp;
  std::cin >> temp;
  return temp;
}

int main() {

  int C[3];
  int ans = 0;
  int min;

  std::cin >> C[0] >> C[1] >> C[2];
  min = std::min(C[0], C[1]);
  min = std::min(min, C[2]);

  ans += min;

  for(int i = 0; i < 3; ++i) {
    C[i] -= min;
  }

  for(;;) {
    std::sort(C, C+3);
    if( C[2] < 3 ) {
      break;
    }
    if( C[1] == 0 ) {
      C[0] += 1;
      C[2] -= 2;
      continue;
    }
    C[2] -= 3;
    C[1] -= 1;
    ans += 1;
  }

  std::cout << ans << std::endl;

  return 0;
}