#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int main(){
    const int INF = 10000;
    int V[4], ans = INF;
    rep(i, 4)cin >> V[i];
    FOR(a, 1, 31)FOR(b, 1, a)FOR(c, 1, b){
        int need = 0;
        vi abc{a,b,c};
        rep(i, 4){
            vi dp(V[i]+1, INF);
            dp[0] = 0;
            each(A, abc){
                FOR(j, A, V[i] + 1){
                    smin(dp[j], dp[j - A]+1);
                }
            }
            need += dp[V[i]];
        }
        smin(ans, need);
    }
    cout << ans << endl;
}