#include <iostream>
//#include<atcoder/all>
#include <numeric>
#include <cmath>
#include <limits>
#include <stdio.h>
#include <iomanip>
#include <string> 
#include <vector>
#include <algorithm>
#include <utility> 
#include <tuple> 
#include <cstdint> 
#include <cstdio> 
#include <map> 
#include <queue>
#include <set> 
#include <stack> 
#include <deque> 
#include <unordered_map> 
#include <unordered_set>
#include <bitset> 
#include <cctype>
//using namespace atcoder;
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<pair<ll, ll>>>;
vector<bool> seen;
bool C = true;
vector<ll> dist;
ll mod = 998244353;


int main() {
	ll A, B, N, M;
	cin >> A >> B >> N >> M;
	if (A < B) {
		cout << A + (B - A) / (M + 1) << endl;
	}
	else {
		cout << B + (A - B) / (N + 1) << endl;
	}
}