#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 28) - 1;
int MOD = 1e9+7;
main(){
    int V[4],num[3];
    rep(i,0,4)cin >> V[i];
    int ans = INF;
    rep(i,1,31)rep(j,i+1,31)rep(k,j+1,31){
        num[0] = i;
        num[1] = j;
        num[2] = k;

        vector<int> dp(31,INF);
        dp[0] = 0;
        rep(l,0,31)rep(m,0,3){
            if(l < num[m])continue;
            dp[l] = min(dp[l], dp[l - num[m]] + 1);
        }
        ans = min(ans, dp[V[0]] + dp[V[1]] + dp[V[2]] + dp[V[3]] );
    }
    cout << ans << endl;
}