#include<bits/stdc++.h>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
using ll = long long;
int A,B,O,W;

void solve(){
	cout<<O+max(A,B)+W<<endl;
}

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cin >> A >> B >> O >> W;
	solve();
}