#include <iostream>
#include <stdio.h>
#include <string>
#include <vector>
#include <set>
#include <cmath>
#include <algorithm>
#define MP make_pair
using ll = long long;
using namespace std;

int main()
{
  int N;
  ll X, A, B;
  cin >> N;
  cin >> X >> A >> B;
  ll max = pow(2, N-1) -1;
  ll n1 = (max - X) / B + 1;
  ll n2 = X / A;
  if(X%A != 0)
    n2++;
  cout << min(n1, n2) << endl;
  return 0;
}