#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int64_t a, b, n, m;
    cin >> a >> b >> n >> m;
    int64_t ans;
    if (a > b)
        ans = b + (a - b) / (n + 1);
    else
        ans = a + (b - a) / (m + 1);
    cout << ans << endl;
    return 0;
}