#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>
#include <set>
#include <map>

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define inf 1e9
typedef long long ll;

using namespace std;


int inputValue(){
    int a;
    cin >> a;
    return a;
};

template <typename T>
void output(T a, int precision) {
    if(precision > 0){
        cout << setprecision(precision)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}

int min_plates(int l, int a, int b, int c){ // length, a < b < c
    
    vector<int> dp(l + 1, inf);
    dp[0] = 0;
    
    rep(i, l - a + 1){
        dp[i + a] = min(dp[i + a], dp[i] + 1);
    }
    rep(i, l - b + 1){
        dp[i + b] = min(dp[i + b], dp[i] + 1);
    }
    rep(i, l - c + 1){
        dp[i + c] = min(dp[i + c], dp[i] + 1);
    }
    
    return dp[l];
}

int main() {
    // source code
    
    vector<int> V(4);
    rep(i, 4){
        V[i] = inputValue(); // 1 - 30
    }
    
    // 1 <= A < B < C <= 30
    
    vector<vector<vector<int>>> ABC(30, vector<vector<int>>(30, vector<int>(30, inf)));
    
    rep(i, 30){
        rep(j, 30){
            rep(k, 30){
                int tmp = 0;
                rep(l, 4){
                    int mp = min_plates(V[l], i + 1, j + 1, k + 1);
                    if (mp == inf) {
                        tmp = inf;
                        break;
                    }
                    tmp += mp;
                }
                ABC[i][j][k] = tmp;
            }
        }
    }
    
    int ret = inf;
    
    rep(i, 30){
        rep(j, 30){
            rep(k, 30){
                ret = min(ret, ABC[i][j][k]);
            }
        }
    }
    
    output(ret, 0);
    
    return 0;
}