import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    }
} Main public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    } main {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int A = scanner.nextInt(); A scanner.nextInt() scanner.nextInt scanner int B = scanner.nextInt(); B scanner.nextInt() scanner.nextInt scanner int C = scanner.nextInt(); C scanner.nextInt() scanner.nextInt scanner int D = scanner.nextInt(); D scanner.nextInt() scanner.nextInt scanner boolean turnT = true; turnT true while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        } 0 < A && 0 < C 0 < A 0 A 0 < C 0 C {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        } if (turnT) {
                C -= B;
            } else {
                A -= D;
            } turnT {
                C -= B;
            } C -= B C B {
                A -= D;
            } A -= D A D turnT = !turnT turnT !turnT turnT System.out.println(A < 1 ? "No" : "Yes") System.out.println System.out System System.out A < 1 ? "No" : "Yes" A < 1 A 1 "No" "Yes" String[] args args public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    }
} public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    }
} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        int D = scanner.nextInt();

        boolean turnT = true;
        while (0 < A && 0 < C) {
            if (turnT) {
                C -= B;
            } else {
                A -= D;
            }
            turnT = !turnT;
        }
        System.out.println(A < 1 ? "No" : "Yes");
    }
}