#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < int(n); i++)
using ll = long long;
using P = pair<int, int>;

int main() {
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    
    ll a, b, n, m; cin >> a >> b >> n >> m;
    cout << min(a, b) + (a >= b ? (a - b) / (n + 1) : (b - a) / (m + 1)) << endl;
    return 0;
}