import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    }
} Main public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    } main {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    } Scanner input = new Scanner(System.in); input new Scanner(System.in) Integer A = input.nextInt(); A input.nextInt() input.nextInt input Integer B = input.nextInt(); B input.nextInt() input.nextInt input Integer C = input.nextInt(); C input.nextInt() input.nextInt input Integer D = input.nextInt(); D input.nextInt() input.nextInt input Integer ConfirmTimeT = (int)Math.ceil((float)C / B); ConfirmTimeT (int)Math.ceil((float)C / B) Math.ceil Math (float)C / B (float)C B Integer ConfirmTimeA = (int)Math.ceil((float)A / D); ConfirmTimeA (int)Math.ceil((float)A / D) Math.ceil Math (float)A / D (float)A D if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No"); ConfirmTimeT <= ConfirmTimeA ConfirmTimeT ConfirmTimeA System.out.println("Yes") System.out.println System.out System System.out "Yes" System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        Integer A = input.nextInt();
        Integer B = input.nextInt();
        Integer C = input.nextInt();
        Integer D = input.nextInt();

        Integer ConfirmTimeT = (int)Math.ceil((float)C / B);
        Integer ConfirmTimeA = (int)Math.ceil((float)A / D);

        if (ConfirmTimeT <= ConfirmTimeA) System.out.println("Yes");
        else System.out.println("No");
    }
}
