import javax.swing.text.html.HTMLDocument;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.nio.Buffer;
import java.util.*;

class Main {
    public static void main(String[] args){
        try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        }
    }
    static void shuffle(int[] a) {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    }
} import javax.swing.text.html.HTMLDocument; HTMLDocument javax.swing.text.html import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.PrintWriter; PrintWriter java.io import java.math.BigInteger; BigInteger java.math import java.nio.Buffer; Buffer java.nio import java.util.*; util.* java class Main {
    public static void main(String[] args){
        try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        }
    }
    static void shuffle(int[] a) {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    }
} Main public static void main(String[] args){
        try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        }
    } main {
        try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        }
    } try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        } Exception e {
            System.out.println("kkkk "+ e.getMessage());
        } System.out.println("kkkk "+ e.getMessage()) System.out.println System.out System System.out "kkkk "+ e.getMessage() "kkkk " e.getMessage() e.getMessage e {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String[] ss=br.readLine().split(" "); ss br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " int h1=Integer.parseInt(ss[0]); h1 Integer.parseInt(ss[0]) Integer.parseInt Integer ss[0] ss 0 int s1=Integer.parseInt(ss[1]); s1 Integer.parseInt(ss[1]) Integer.parseInt Integer ss[1] ss 1 int h2=Integer.parseInt(ss[2]); h2 Integer.parseInt(ss[2]) Integer.parseInt Integer ss[2] ss 2 int s2=Integer.parseInt(ss[3]); s2 Integer.parseInt(ss[3]) Integer.parseInt Integer ss[3] ss 3 double d=(h2/(double)s1); d (h2/(double)s1) h2 (double)s1 if(d!=(int)d){
                d=(int)d + 1;
            } d!=(int)d d (int)d {
                d=(int)d + 1;
            } d=(int)d + 1 d (int)d + 1 (int)d 1 double e=(h1/(double)s2); e (h1/(double)s2) h1 (double)s2 if(e!=(int)e){
                e=(int)e+1;
            } e!=(int)e e (int)e {
                e=(int)e+1;
            } e=(int)e+1 e (int)e+1 (int)e 1 if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            } d<=e d e {
                System.out.println("Yes");
            } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
                System.out.println("No");
            } System.out.println("No") System.out.println System.out System System.out "No" String[] args args static void shuffle(int[] a) {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    } shuffle {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    } Random get = new Random(); get new Random() for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        } int i = 0; int i = 0; i 0 i < a.length i a.length a a.length i++ i++ i {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        } {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        } int r = get.nextInt(a.length); r get.nextInt(a.length) get.nextInt get a.length a a.length int temp = a[i]; temp a[i] a i a[i] = a[r] a[i] a i a[r] a r a[r] = temp a[r] a r temp int[] a a
import javax.swing.text.html.HTMLDocument;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.nio.Buffer;
import java.util.*;

class Main {
    public static void main(String[] args){
        try {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String[] ss=br.readLine().split(" ");
            int h1=Integer.parseInt(ss[0]);
            int s1=Integer.parseInt(ss[1]);
            int h2=Integer.parseInt(ss[2]);
            int s2=Integer.parseInt(ss[3]);
            double d=(h2/(double)s1);
            if(d!=(int)d){
                d=(int)d + 1;
            }
            double e=(h1/(double)s2);
            if(e!=(int)e){
                e=(int)e+1;
            }
            if(d<=e){
                System.out.println("Yes");
            }else{
                System.out.println("No");
            }
        } catch (Exception e) {
            System.out.println("kkkk "+ e.getMessage());
        }
    }
    static void shuffle(int[] a) {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    }
}