import java.io.*;
import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int d=sc.nextInt();
    while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    }  
  }
}   import java.io.*; io.* java import java.util.*; util.* java class Main
{
  public static void main(String args[])
  {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int d=sc.nextInt();
    while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    }  
  }
} Main public static void main(String args[])
  {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int d=sc.nextInt();
    while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    }  
  } main {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int d=sc.nextInt();
    while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    }  
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) int a=sc.nextInt(); a sc.nextInt() sc.nextInt sc int b=sc.nextInt(); b sc.nextInt() sc.nextInt sc int c=sc.nextInt(); c sc.nextInt() sc.nextInt sc int d=sc.nextInt(); d sc.nextInt() sc.nextInt sc while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    } a>=0 || c>=0 a>=0 a 0 c>=0 c 0 {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    } c-=b c b if(c<=0)
       {
         System.out.println("Yes");
         break;
       } c<=0 c 0 {
         System.out.println("Yes");
         break;
       } System.out.println("Yes") System.out.println System.out System System.out "Yes" break; a-=d a d if(a<=0)
      {
        System.out.println("No");
        break;
      } a<=0 a 0 {
        System.out.println("No");
        break;
      } System.out.println("No") System.out.println System.out System System.out "No" break; String args[] args
import java.io.*;
import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner sc=new Scanner(System.in);
    int a=sc.nextInt();
    int b=sc.nextInt();
    int c=sc.nextInt();
    int d=sc.nextInt();
    while(a>=0 || c>=0)
    {
      c-=b;
      if(c<=0)
       {
         System.out.println("Yes");
         break;
       } 
      a-=d;
      if(a<=0)
      {
        System.out.println("No");
        break;
      }
    }  
  }
}  
