#include <algorithm>
#include <bitset>
#include <cmath>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <utility>
#include <vector>

using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;

ll c2(ll n) { return n * (n - 1) / 2; }

int main() {
    std::cin.tie(0)->sync_with_stdio(0);
    int a, b, o, w;
    cin >> a >> b >> o >> w;

    cout << max((o + a + w), (o + b + w)) << endl;
    return 0;
}