import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    }
} Main public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    } main {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    } int A A B B C C D; D Scanner sc = new Scanner(System.in); sc new Scanner(System.in) A = sc.nextInt() A sc.nextInt() sc.nextInt sc B = sc.nextInt() B sc.nextInt() sc.nextInt sc C = sc.nextInt() C sc.nextInt() sc.nextInt sc D = sc.nextInt() D sc.nextInt() sc.nextInt sc if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        } B >= C B C System.out.println("Yes") System.out.println System.out System System.out "Yes" {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        } int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0; check ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0 ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) (C/B+(C%B == 0 ? 0 : 1)) C/B C B (C%B == 0 ? 0 : 1) C%B == 0 C%B C B 0 0 1 (A/D+(A%D == 0 ? 0 : 1)) A/D A D (A%D == 0 ? 0 : 1) A%D == 0 A%D A D 0 0 1 1 0 switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          } check case 1: 1 case 1: System.out.println("Yes") System.out.println System.out System System.out "Yes" break; case 0: 0 case 0: System.out.println("No") System.out.println System.out System System.out "No" break; String[] args args public class Main {
    public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    }
} public class Main {
    public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int A, B, C, D;
        Scanner sc = new Scanner(System.in);
        A = sc.nextInt();
        B = sc.nextInt();
        C = sc.nextInt();
        D = sc.nextInt();
        if(B >= C) System.out.println("Yes");
        else
        {
          int check = ((C/B+(C%B == 0 ? 0 : 1)) <= (A/D+(A%D == 0 ? 0 : 1))) ? 1 : 0;
          switch (check)
          {
              case 1:
                  System.out.println("Yes");
                  break;
              case 0:
                  System.out.println("No");
                  break;
          }

        }

    }
}
