import java.util.*;
public class Main{


	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	}

} import java.util.*; util.* java public class Main{


	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	}

} Main public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	} main {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long s  =sc.nextLong(); s sc.nextLong() sc.nextLong sc long w  =sc.nextLong(); w sc.nextLong() sc.nextLong sc long c  =sc.nextLong(); c sc.nextLong() sc.nextLong sc long d  =sc.nextLong(); d sc.nextLong() sc.nextLong sc int i  =-1; i -1 1 while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		} true {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		} i++ i if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			} i%2==0 i%2 i 2 0 {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			} c-=w c w 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; {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			} s-=d s d if(s<=0) {
				System.out.println("No");
				break;} s<=0 s 0 {
				System.out.println("No");
				break;} 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) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	}

} public class Main{


	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	}

} Main
import java.util.*;
public class Main{


	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);

		long s  =sc.nextLong();
		long w  =sc.nextLong();
		long c  =sc.nextLong();
		long d  =sc.nextLong();
	  int i  =-1; 
		while(true) {
i++;
			if(i%2==0) {
				c-=w;
				if(c<=0) {
					System.out.println(" Yes");
break;
				}
				
			}else {
				s-=d;
				if(s<=0) {
				System.out.println("No");
				break;}
			}
			
		
		}
	}

}
