#include <iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<iomanip>
#include<map>
#include<random>
#include<complex>
#include<math.h>
#include<functional>
#include<stack>
#include<queue>
#include<set>
#include <cassert>
using namespace std;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define req(i,n) for(int i = 1;i <=  n; i++)
#define rrep(i,n) for(ll i = n-1;i >= 0;i--)
#define ALL(obj) begin(obj), end(obj)
#define RALL(a) rbegin(a),rend(a)
typedef long long ll;
typedef long double ld;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1e18;
const int inf = 0x3fffffff;
const int MAX = 2010000;
const int MOD = 998244353;
ll fac[MAX], finv[MAX], inv[MAX];
void COMint() {
    fac[0] = fac[1] = 1; inv[1] = 1;
    finv[0] = finv[1] = 1;
    for (int i = 2; i < MAX; i++) {
        fac[i] = fac[i - 1] * i % MOD;
        inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
        finv[i] = finv[i - 1] * inv[i] % MOD;
    }
}
ll COM(int n, int k) {
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll a, b, n, m,ans =0; cin >> a >> b >> n >> m;
    ans = min(a, b);
    if (a == b) cout << a << endl;
    else {
        if (a > b) {
            cout << b + (a - b) / (n + 1) << endl;
        }
        else {
            cout << a + (b - a) / (m + 1) << endl;
        }
    }
}