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

int main() {
	int a, b, c, d;
	cin >> a >> b >> c >> d;

	int n = 0;
	for (int i = 1; i < a+1; i++) {
		if ((i * c) <= b) {
			if ((i * c + i) <= d) {
				n = i;
			}
		}
		else {
			break;
		}
	}

	cout << n << endl;
}