#include<sstream>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())
#define indexOf(v,x) (find(all(v),x)-v.begin())



int main(){
	int dp[31];
	int v[4],a[3];
	int ans=INF;
	rep(i,4)cin>>v[i];
	rep(i1,31)rep(i2,31)rep(i3,31){
		fill(dp,dp+31,114514);
		dp[0]=0;
		a[0]=i1;a[1]=i2;a[2]=i3;
		rep(j,31){
			rep(k,3){
				if(j+a[k]<31)dp[j+a[k]]=min(dp[j+a[k]],dp[j]+1);
			}
		}
		ans=min(ans,dp[v[0]]+dp[v[1]]+dp[v[2]]+dp[v[3]]);
	}
	cout<<ans<<endl;
	return 0;
}