import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	}
	public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	}
	public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	}
	public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	}
	public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	}
} Main public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	} main {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	} Scanner input = new Scanner(System.in); input new Scanner(System.in) int A = input.nextInt(); A input.nextInt() input.nextInt input int B = input.nextInt(); B input.nextInt() input.nextInt input int C = input.nextInt(); C input.nextInt() input.nextInt input int D = input.nextInt(); D input.nextInt() input.nextInt input takahasi(A,B,C,D) takahasi A B C D String[] args args public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	} takahasi {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	} C-=B C B if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		} C<=0 C 0 {
			System.out.println("Yes");
		} System.out.println("Yes") System.out.println System.out System System.out "Yes" {
			aoki(A,B,C,D);
		} aoki(A,B,C,D) aoki A B C D int A A int B B int C C int D D public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	} aoki {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	} A-=D A D if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		} A<=0 A 0 {
			System.out.println("No");
		} System.out.println("No") System.out.println System.out System System.out "No" {
			takahasi(A,B,C,D);
		} takahasi(A,B,C,D) takahasi A B C D int A A int B B int C C int D D public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	}
	public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	}
	public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	}
} public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	}
	public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	}
	public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	}
} Main
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int A = input.nextInt();
		int B = input.nextInt();
		int C = input.nextInt();
		int D = input.nextInt();
		
		takahasi(A,B,C,D);
		
	}
	public static void takahasi(int A,int B,int C,int D) {
		C-=B;
		if(C<=0) {
			System.out.println("Yes");
		}
		else {
			aoki(A,B,C,D);
		}
	}
	public static void aoki(int A,int B,int C,int D) {
		A-=D;
		if(A<=0) {
			System.out.println("No");
		}
		else {
			takahasi(A,B,C,D);
		}
	}
}
