import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    }
} import java.util.*; util.* java import java.util.stream.*; stream.* java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    } main {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a = sc.nextInt() a sc.nextInt() sc.nextInt sc b = sc.nextInt() b sc.nextInt() sc.nextInt sc c = sc.nextInt() c sc.nextInt() sc.nextInt sc d = sc.nextInt(); d sc.nextInt() sc.nextInt sc int s = 0; s 0 while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        } a > 0 && c > 0 a > 0 a 0 c > 0 c 0 {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        } if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            } s == 0 s 0 {
                c -= b;
                s = 1;
            } c -= b c b s = 1 s 1 {
                a -= d;
                s = 0;
            } a -= d a d s = 0 s 0 System.out.println(a > 0 ? "Yes" : "No") System.out.println System.out System System.out a > 0 ? "Yes" : "No" a > 0 a 0 "Yes" "No" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    }
} Main
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt(),
            b = sc.nextInt(),
            c = sc.nextInt(),
            d = sc.nextInt();

        int s = 0;
        while (a > 0 && c > 0) {
            if (s == 0) {
                c -= b;
                s = 1;
            }
            else {
                a -= d;
                s = 0;
            }
        }

        System.out.println(a > 0 ? "Yes" : "No");
    }
}