#include <iostream> #include <vector> #include <map> #include <set> #include <queue> #include <string> #include <iomanip> #include <algorithm> #include <cmath> #include <stdio.h> using namespace std; #define int long long int MOD = 1000000007; signed main() { cin.tie(0); ios::sync_with_stdio(false); int N, X, A, B; cin >> N; cin >> X; cin >> A; cin >> B; int res = (X + A - 1) / A; cerr << res << endl; cerr << (((int)1 << (N - 1)) - X + B - 1) / B << endl; res = min(res, (((int)1 << (N - 1)) - X + B - 1) / B); cout << res << endl; }