#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

int sub(int a,int b,int c,int n){
	int ret = INF/2;
	for(int i=n/c;i>=0;i--){
		for(int j=n/b;j>=0;j--){
			for(int k=n/a;k>=0;k--){
				if(c*i+b*j+a*k == n){
					ret = min(ret,i+j+k);
				}
			}
		}
	}
	return ret;
}
int func(int a,int b,int c,vector<int>& v){
	int ret = 0;
	for(int l=0;l<4;l++){
		ret += sub(a,b,c,v[l]);
	}
	return ret;
}

int main(void) {
	vector<int> v(4);
	cin >> v[0] >> v[1] >> v[2] >> v[3];
	sort(begin(v),end(v));

	//30^3 * 

	int ret = INF;
	for(int a=1;a<=30;a++){
		for(int b=a+1;b<=30;b++){
			for(int c=b+1;c<=30;c++){
				ret = min(ret,func(a,b,c,v));
			}
		}
	}
	assert(ret < INF/2);
	cout << ret << endl;
	return 0;
}