import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
}} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
}} Main public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
} main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    } catch (Exception e) {
    } Exception e {
    } {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    } String isWin = ""; isWin "" int [] a = new int [4]; a new int [4] 4 String  lines = br.readLine(); lines br.readLine() br.readLine br String[] strs = lines.trim().split("\\s+"); strs lines.trim().split("\\s+") lines.trim().split lines.trim() lines.trim lines "\\s+" for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       } int i = 0; int i = 0; i 0 i < strs.length i strs.length strs strs.length i++ i++ i {
       a[i] = Integer.parseInt(strs[i]);
       } {
       a[i] = Integer.parseInt(strs[i]);
       } a[i] = Integer.parseInt(strs[i]) a[i] a i Integer.parseInt(strs[i]) Integer.parseInt Integer strs[i] strs i int taka = (a[0]+a[3]-1)/a[3]; taka (a[0]+a[3]-1)/a[3] (a[0]+a[3]-1) a[0]+a[3] a[0] a 0 a[3] a 3 1 a[3] a 3 int aoki = (a[2]+a[1]-1)/a[1]; aoki (a[2]+a[1]-1)/a[1] (a[2]+a[1]-1) a[2]+a[1] a[2] a 2 a[1] a 1 1 a[1] a 1 System.out.println(taka>=aoki?"Yes" : "No" ) System.out.println System.out System System.out taka>=aoki?"Yes" : "No" taka>=aoki taka aoki "Yes" "No" String[]args args public class Main {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
}} public class Main {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
}} Main
import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[]args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
       String isWin = "";
    
       int [] a = new int [4];
     
       
       String  lines = br.readLine();    
    
       String[] strs = lines.trim().split("\\s+");
      
       for (int i = 0; i < strs.length; i++) {
       a[i] = Integer.parseInt(strs[i]);
       }
  
    int taka = (a[0]+a[3]-1)/a[3];
    int aoki = (a[2]+a[1]-1)/a[1];
    
    
    System.out.println(taka>=aoki?"Yes" : "No" ); 
     
    }catch (Exception e) {
    }
    
}}