#include<bits/stdc++.h>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
using ll = long long;
using ld = long double;
#ifdef LOCAL
#include <dump/dump.hpp>
#else
#define dump(...) void(0)
#endif
using mint = modint998244353;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int A, B, O, W; cin >> A >> B >> O >> W;
    int ans = max(O + A + W, O + B + W);
    cout << ans << endl;
}