#include <bits/stdc++.h>
using namespace std;

int main() {
    int V[4];
    for (int i = 0; i < 4; i++) {
        cin >> V[i];
    }

    int ans = 10000;
    for (int A = 1; A < 31; A++) {
        for (int B = A + 1; B < 31; B++) {
            for (int C = B + 1; C < 31; C++) {
                int dp[40];
                for (int i = 0; i < 40; i++) {
                    dp[i] = 10000;
                }
                dp[0] = 0;
                for (int i = 0; i < 31; i++) {
                    if (i >= A) dp[i] = min(dp[i], dp[i - A] + 1);
                }
                for (int i = 0; i < 31; i++) {
                    if (i >= B) dp[i] = min(dp[i], dp[i - B] + 1);
                }
                for (int i = 0; i < 31; i++) {
                    if (i >= C) dp[i] = min(dp[i], dp[i - C] + 1);
                }
                ans = min(ans, dp[V[0]] + dp[V[1]] + dp[V[2]] + dp[V[3]]);
            }
        }
    }
    cout << ans << endl;
}