import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int ans = 0;
        int a = sc.nextInt();
        int b = sc.nextInt();
        int c = sc.nextInt();
        int d = sc.nextInt();
        for( ; ans <= a; ans++) {
            if(ans * c > b) {
                ans--;
                break;
            }
            if(ans * (c + 1) > d) {
                ans--;
                break;
            }
        }
        System.out.println(ans);
    }
}