#include <bits/stdc++.h>
using namespace std;
const int INF = 1000;
int main(){
  vector<int> V(4);
  for (int i = 0; i < 4; i++){
    cin >> V[i];
  }
  int ans = INF;
  vector<int> L(3);
  for (L[0] = 1; L[0] <= 30; L[0]++){
    for (L[1] = 1; L[1] <= 30; L[1]++){
      for (L[2] = 1; L[2] <= 30; L[2]++){
        vector<int> dp(31, INF);
        dp[0] = 0;
        for (int i = 1; i <= 30; i++){
          for (int j = 0; j < 3; j++){
            if (i >= L[j]){
              dp[i] = min(dp[i], dp[i - L[j]] + 1);
            }
          }
        }
        int sum = 0;
        for (int i = 0; i < 4; i++){
          sum += dp[V[i]];
        }
        ans = min(ans, sum);
      }
    }
  }
  cout << ans << endl;
}