#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
using namespace std;

#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define uniq(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef pair<int, int> P;
typedef unsigned int uint;
typedef unsigned long long ull;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};

const int inf = 100000009;
const double eps = 1e-8;

int main() {
    int maxi = 0;
    int vs[4];
    for (int i = 0; i < 4; i++) {
	scanf("%d", &vs[i]);
	maxi = max(maxi, vs[i]);
    }
    int res = inf;
    for (int a = 1; a <= maxi; a++) {
	for (int b = a; b <= maxi; b++) {
	    for (int c= b; c <= maxi; c++) {
		int v[3] = {a, b, c};
		int dp[maxi+1];
		fill_n(dp, maxi+1, inf);
		dp[0] = 0;
		for (int i = 0; i < maxi; i++) {
		    if (dp[i] < inf) {
			for (int j = 0; j < 3; j++)
			    if (i + v[j] <= maxi)
				dp[i+v[j]] = min(dp[i+v[j]], dp[i]+1);
		    }
		}
		int sum = 0;
		for (int i = 0; i < 4; i++)
		    sum += dp[vs[i]];
		res = min(res, sum);
	    }
	}
    }
    printf("%d\n", res);
}