#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
#include <numeric>
#include <string>

#define V_MAX 30

using namespace std;

int main(void)
{
    int V[4];
    for (int i = 0; i < 4; i++) {
        cin >> V[i];
    }
    int ret = INT_MAX;
    int A[3];
    for (A[0] = 1; A[0] <= V_MAX; A[0]++) {
        for (A[1] = A[0] + 1; A[1] <= V_MAX; A[1]++) {
            for (A[2] = A[1] + 1; A[2] <= V_MAX; A[2]++) {
                int dp[V_MAX + 1];
                dp[0] = 0;
                for (int i = 1; i <= V_MAX; i++) {
                    dp[i] = 4 * V_MAX;
                    for (int j = 0; j < 3; j++) {
                        if (A[j] <= i) {
                            dp[i] = min(dp[i], dp[i - A[j]] + 1);
                        }
                    }
                }
                int x = 0;
                for (int i = 0; i < 4; i++) {
                    x += dp[V[i]];
                }
                ret = min(ret, x);
            }
        }
    }
    printf("%d\n", ret);
    return 0;
}