#include <bits/stdc++.h>
#include <cmath>
#include <climits>
#include <cstdio>

using namespace std;

#define endl '\n'
#define PB push_back
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define RBP(i,a) for(auto& i : a)
#define rangej(x,y,z) (x<=z&&z<=y)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define F first
#define S second
#define SNP string::npos
#define WRC(hoge,x) cout << "Case #" << (hoge)+1 << ": " << x << endl
#define ten(n) (LL)pow(10,n)
#define INF ten(7)

typedef pair<int,int> P;
typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<LL,LL> LP;

void ios_init(){ ios::sync_with_stdio(false); cin.tie(0);	
	//cout.setf(ios::fixed);
	//cout.precision(12);
}

int v[4];

int dp[33];

int main()
{
	ios_init();
	REP(i,4)	cin >> v[i];
	int ans = INF;
	FOR(a,1,31) FOR(b,a+1,31) FOR(c,b+1,31){
		int ar[] = {a,b,c};
		fill(dp,dp+31,INF);
		dp[0] = 0;
		REP(i,3){
			FOR(j,ar[i],31){
				dp[j] = min(dp[j-ar[i]]+1,dp[j]);
			}
		}
		int t = 0;
		REP(i,4)	t += dp[v[i]];
		ans = min(ans,t);
	}
	cout << ans << endl;
	return 0;
}