#include <bits/stdc++.h>

using namespace std;

using i64 = long long;

#define yn(pope) (pope ? "Yes" : "No")

#define rep(i, n, m) for (int i = (n); i < (m); i++)
#define rrep(i, n, m) for (int i = (n); i > m; i--)

#define IINF (1 << 30)
#define INF (1ll << 60)

#define all(v) v.begin(), v.end()

int main() {
  int a, b, o, w; cin >> a >> b >> o >> w;

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

  return 0;
}