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

#define loop(i,a,b) for(int i=(a);i<int(b);i++)
#define rep(i,b) loop(i,0,b)

int const inf = 100000000;

int solve(int x, int y, int z, int a, int b, int c, int d){
    int dp[32];
    rep(i,32) dp[i] = inf;
    dp[0] = 0;
    for(int e : {x,y,z}) loop(i,e,32) dp[i] = min(dp[i],dp[i-e]+1);
    return dp[a]+dp[b]+dp[c]+dp[d];
}

int main(){
    int a,b,c,d;
    cin >> a >> b >> c >> d;
    int ans = inf;
    for(int i=1;i<=30;i++){
        loop(j,1,i){
            loop(k,1,j){
                ans = min(ans,solve(i,j,k,a,b,c,d));
            }
        }
    }
    cout << ans << endl;
}