import java.util.Scanner;

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