import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	} main {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int[] a = new int[2]; a new int[2] 2 int[] b = new int[2]; b new int[2] 2 boolean act = true; act true a[0] = sc.nextInt() a[0] a 0 sc.nextInt() sc.nextInt sc a[1] = sc.nextInt() a[1] a 1 sc.nextInt() sc.nextInt sc b[0] = sc.nextInt() b[0] b 0 sc.nextInt() sc.nextInt sc b[1] = sc.nextInt() b[1] b 1 sc.nextInt() sc.nextInt sc while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		} a[0] > 0 && b[0] > 0 a[0] > 0 a[0] a 0 0 b[0] > 0 b[0] b 0 0 {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		} if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			} act {
				b[0] -= a[1];
				act = !act;
			} b[0] -= a[1] b[0] b 0 a[1] a 1 act = !act act !act act {
				a[0] -= b[1];
				act = !act;
			} a[0] -= b[1] a[0] a 0 b[1] b 1 act = !act act !act act if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		} b[0] <= 0 b[0] b 0 0 {
			System.out.println("Yes");
		} System.out.println("Yes") System.out.println System.out System System.out "Yes" if (a[0] <= 0) {
			System.out.println("No");
		} a[0] <= 0 a[0] a 0 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 sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int[] a = new int[2];
		int[] b = new int[2];
		boolean act = true;
		a[0] = sc.nextInt();
		a[1] = sc.nextInt();
		b[0] = sc.nextInt();
		b[1] = sc.nextInt();
		while (a[0] > 0 && b[0] > 0) {
			if (act) {
				b[0] -= a[1];
				act = !act;
			} else {
				a[0] -= b[1];
				act = !act;
			}
		}
		if (b[0] <= 0) {
			System.out.println("Yes");
		} else if (a[0] <= 0) {
			System.out.println("No");
		}
	}
}
