#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using intt = int64_t;
intt sum(const long &a, const long &b) { return (a + b) * (b - a + 1) / 2; }
vector<char> alphabet={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
int main() {
cout << fixed << setprecision(10);
  intt a,b,n,m;
  cin>>a>>b>>n>>m;
  intt x=min(a,b);
  intt y=max(a,b)-x;
  if(a>b){
      x+=y/(n+1);
  }
  else if(b>a){
      x+=y/(m+1);
  }
  cout<<x<<endl;
}