
import java.util.Scanner;

public class Main{
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=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);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=0) {
			System.out.println("No");
		}

	}
} Main public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=0) {
			System.out.println("No");
		}

	} main {

		Scanner scan = new Scanner(System.in);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=0) {
			System.out.println("No");
		}

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String num = scan.nextLine(); num scan.nextLine() scan.nextLine scan String[] numbers = num.split(" "); numbers num.split(" ") num.split num " " double A = Integer.parseInt(numbers[0]); A Integer.parseInt(numbers[0]) Integer.parseInt Integer numbers[0] numbers 0 double B = Integer.parseInt(numbers[1]); B Integer.parseInt(numbers[1]) Integer.parseInt Integer numbers[1] numbers 1 double C = Integer.parseInt(numbers[2]); C Integer.parseInt(numbers[2]) Integer.parseInt Integer numbers[2] numbers 2 double D = Integer.parseInt(numbers[3]); D Integer.parseInt(numbers[3]) Integer.parseInt Integer numbers[3] numbers 3 while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		} true {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		} C=C-B C C-B C B if(C<=0) {
				break;
			} C<=0 C 0 {
				break;
			} break; A=A-D A A-D A D if(A<=0) {
				break;
			} A<=0 A 0 {
				break;
			} break; 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" if(A<=0) {
			System.out.println("No");
		} A<=0 A 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);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=0) {
			System.out.println("No");
		}

	}
} public class Main{
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=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);
		String num = scan.nextLine();
		String[] numbers = num.split(" ");
		double A = Integer.parseInt(numbers[0]);
		double B = Integer.parseInt(numbers[1]);
		double C = Integer.parseInt(numbers[2]);
		double D = Integer.parseInt(numbers[3]);

		while(true) {
			C=C-B;
			if(C<=0) {
				break;
			}
			A=A-D;
			if(A<=0) {
				break;
			}
		}

		if(C<=0) {
			System.out.println("Yes");
		}
		if(A<=0) {
			System.out.println("No");
		}

	}
}
