#include <bits/stdc++.h>
#define ll long long
#define INF 100000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;--i)
#define srep(i,s,t) for(int i=(int)(s);i<(int)(t);++i)
#define each(a,b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define len(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define cmx(x,y) x=max(x,y)
#define cmn(x,y) x=min(x,y)
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<double> vd;
typedef vector<P> vp;

const int MAX_N = 100005;
int dp[31];

void ks(int* ag)
{
    rep(j,31){
        dp[j] = INF;
    }
    dp[0] = 0;
    rep(i,3){
        rep(j,31){
            if(j+ag[i] <= 30){
                cmn(dp[j+ag[i]],dp[j]+1);
            }
        }
    }
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int a,b,c,d;
    cin >> a >> b >> c >> d;
    int mn = INF;
    srep(i,1,31){
        srep(j,1,31){
            srep(k,1,31){
                int ag[3] = {i,j,k};
                ks(ag);
                cmn(mn,dp[a]+dp[b]+dp[c]+dp[d]);
            }
        }
    }
    cout << mn << endl;
    return 0;
}