#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define INF 120000000

using namespace std;

typedef pair<int, int> P;
typedef long long int LL;

int main() {
    LL n, x, a, b;
    cin >> n >> x >> a >> b;
    LL mx = pow(2, n - 1) - 1;
    LL cnt = min((mx - x) / b + 1, x / a + 1);
    cout << cnt << endl;

    return 0;
}