import java.util.Scanner;

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

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble(); double B = sc.nextDouble(); double C = sc.nextDouble(); double D = sc.nextDouble();

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble(); double B = sc.nextDouble(); double C = sc.nextDouble(); double D = sc.nextDouble();

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble(); double B = sc.nextDouble(); double C = sc.nextDouble(); double D = sc.nextDouble();

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double A = sc.nextDouble(); A sc.nextDouble() sc.nextDouble sc double B = sc.nextDouble(); B sc.nextDouble() sc.nextDouble sc double C = sc.nextDouble(); C sc.nextDouble() sc.nextDouble sc double D = sc.nextDouble(); D sc.nextDouble() sc.nextDouble sc if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        } Math.ceil(A/D)>=Math.ceil(C/B) Math.ceil(A/D) Math.ceil Math A/D A D Math.ceil(C/B) Math.ceil Math C/B C B {
            System.out.println("Yes");
        } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
            System.out.println("No");
        } System.out.println("No") System.out.println System.out System System.out "No" sc.close() sc.close sc String[] args args public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble(); double B = sc.nextDouble(); double C = sc.nextDouble(); double D = sc.nextDouble();

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    }
} public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble(); double B = sc.nextDouble(); double C = sc.nextDouble(); double D = sc.nextDouble();

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    }
} Main
import java.util.Scanner;

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

        if(Math.ceil(A/D)>=Math.ceil(C/B)){
            System.out.println("Yes");
        } else{
            System.out.println("No");
        }

        sc.close();
    }
}