#include <iomanip>
#include <cmath>
#include <sstream>
#include <unordered_map>
#include <unordered_set>
#include <deque>
#include <vector>
#include <bitset>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include<iostream>
#include<map>
#include<algorithm>

using namespace std;

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

	int ans = min(a, b / c);

	if (ans + ans * c <= d) {
		cout << ans << endl;
	}
	else {
		while (ans+ans*c>d) {
			ans--;
		}
		cout << ans << endl;
	}

	return 0;
}