import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String data = sc.nextLine(); data sc.nextLine() sc.nextLine sc String[] array = data.split(" "); array data.split(" ") data.split data " " int a = Integer.parseInt(array[0]); a Integer.parseInt(array[0]) Integer.parseInt Integer array[0] array 0 int b = Integer.parseInt(array[1]); b Integer.parseInt(array[1]) Integer.parseInt Integer array[1] array 1 int c = Integer.parseInt(array[2]); c Integer.parseInt(array[2]) Integer.parseInt Integer array[2] array 2 int d = Integer.parseInt(array[3]); d Integer.parseInt(array[3]) Integer.parseInt Integer array[3] array 3 String result = "No"; result "No" int count_a = 0; count_a 0 int count_c = 0; count_c 0 while(a > 0)
        {
            a -= d;
            count_a++;
        } a > 0 a 0 {
            a -= d;
            count_a++;
        } a -= d a d count_a++ count_a while(c > 0)
        {
            c -= b;
            count_c++;
        } c > 0 c 0 {
            c -= b;
            count_c++;
        } c -= b c b count_c++ count_c if(count_a >= count_c)
        {
            result = "Yes";
        } count_a >= count_c count_a count_c {
            result = "Yes";
        } result = "Yes" result "Yes" System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String data = sc.nextLine();
        
        String[] array = data.split(" ");
        int a = Integer.parseInt(array[0]);
        int b = Integer.parseInt(array[1]);
        int c = Integer.parseInt(array[2]);
        int d = Integer.parseInt(array[3]);
        
        String result = "No";
        
        int count_a = 0;
        int count_c = 0;
        while(a > 0)
        {
            a -= d;
            count_a++;
        }
        while(c > 0)
        {
            c -= b;
            count_c++;
        }
        
        if(count_a >= count_c)
        {
            result = "Yes";
        }
        
        System.out.println(result);
    }
}
