#include <bits/stdc++.h>
using namespace std;
#define all(v) (v).begin(), (v).end()
using ll = long long;
using ld = long double;
using pint = pair<int, int>;
using pll = pair<ll, ll>;

int main() {
    int a, b, o, w;
    cin >> a >> b >> o >> w;
    int ans = max(o + a + w, o + b + w);
    cout << ans << endl;
}