import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    }
    static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    }
}
 import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    }
    static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    }
} Main public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    } main {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int a = scan.nextInt(); a scan.nextInt() scan.nextInt scan int b = scan.nextInt(); b scan.nextInt() scan.nextInt scan int c = scan.nextInt(); c scan.nextInt() scan.nextInt scan int d = scan.nextInt(); d scan.nextInt() scan.nextInt scan scan.close() scan.close scan String message = turn(a,d) >= turn(c, b) ? "Yes" : "No"; message turn(a,d) >= turn(c, b) ? "Yes" : "No" turn(a,d) >= turn(c, b) turn(a,d) turn a d turn(c, b) turn c b "Yes" "No" System.out.println(message) System.out.println System.out System System.out message String[] args args static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    } turn {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    } return hp / atk + (hp % atk == 0 ? 0 : 1); hp / atk + (hp % atk == 0 ? 0 : 1) hp / atk hp atk (hp % atk == 0 ? 0 : 1) hp % atk == 0 hp % atk hp atk 0 0 1 int hp hp int atk atk public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    }
    static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    }
    static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
        int c = scan.nextInt();
        int d = scan.nextInt();
        scan.close();

        String message = turn(a,d) >= turn(c, b) ? "Yes" : "No";
        System.out.println(message);
    }
    static int turn(int hp, int atk) {
        return hp / atk + (hp % atk == 0 ? 0 : 1);
    }
}

