#include <cstdio>
#include <algorithm>
using namespace std;

class range {private: struct I{int x;int operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:range(int n):i({0}),n({n}){}range(int i,int n):i({i}),n({n}){}I& begin(){return i;}I& end(){return n;}};

const int inf = 19921223;
const int N = 33;

int main(void) {
  vector<int> v(4);
  for(int i : range(4)) { scanf("%d", &v[i]); }
  int res = inf;
  for(int a : range(1, N)) {
    for(int b : range(a+1, N)) {
      for(int c : range(b+1, N)) {
        vector<int> dp(N, inf);
        for(int x : range(N)) {
          if(x % a == 0) { dp[x] = min(dp[x], x / a); }
          if(x % b == 0) { dp[x] = min(dp[x], x / b); }
          if(x % c == 0) { dp[x] = min(dp[x], x / c); }
          for(int n : range(N)) {
            for(int p : range(n)) {
              dp[n] = min(dp[n], dp[p] + dp[n-p]);
            }
          }
          int tmp = 0;
          for(int i : range(4)) {
            tmp += dp[v[i]];
          }
          res = min(res, tmp);
        }
      }
    }
  }
  printf("%d\n", res);
  return 0;
}