#include <bits/stdc++.h>
using namespace std;

typedef long long int ll;

#define repl(i,a,b) for(int i=(int)a;i<(int)b;i++)
#define rep(i,n) repl(i,0,n)

int main(){
  ll n,a,b,x;
  cin>>n>>x>>a>>b;
  ll m=pow(2LL,n-1)-1;
  cout<<min((x+a)/a,(m-x+b)/b)<<endl;
  return 0;
}