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();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 }
} 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();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 }
} 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();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 } main {
Scanner scan = new Scanner(System.in);
  int A = scan.nextInt();
  int B = scan.nextInt();
  int C = scan.nextInt(); 
  int D = scan.nextInt();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 } 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 while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  } (A>0) && (C>0) (A>0) A 0 (C>0) C 0 {
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  } C=C-B C C-B C B if (C<=0){
    System.out.println("Yes");} C<=0 C 0 {
    System.out.println("Yes");} System.out.println("Yes") System.out.println System.out System System.out "Yes" A=A-D A A-D A D if ((A<=0) && (C>0)){
    System.out.println("No");} (A<=0) && (C>0) (A<=0) A 0 (C>0) C 0 {
    System.out.println("No");} 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 scan = new Scanner(System.in);
  int A = scan.nextInt();
  int B = scan.nextInt();
  int C = scan.nextInt(); 
  int D = scan.nextInt();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 }
} 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();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 }
} 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();
  while ((A>0) && (C>0)){
   C=C-B;
   if (C<=0){
    System.out.println("Yes");}
   A=A-D;
   if ((A<=0) && (C>0)){
    System.out.println("No");}
  }
 }
}