#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;

int main()
{
    long long A,B,N,M;
    cin >> A >> B >> N >> M;
    unsigned long long ans=0;
    ans += min(A,B);
    unsigned long long tmp=0;
    if(A < B)
    {
        tmp = (B-A)/(M+1);
    }
  	if(B < A)
    {
      tmp = (A - B)/(N+1);
    }
    ans += tmp;
    cout << ans;
    
    return 0;
}