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

public class Main {
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    }
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    }
} Main public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    } main {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out)); out new PrintWriter(new OutputStreamWriter(System.out)) String[] str = br.readLine().split(" "); str br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " int tHP = Integer.parseInt(str[0]); tHP Integer.parseInt(str[0]) Integer.parseInt Integer str[0] str 0 int tATK = Integer.parseInt(str[1]); tATK Integer.parseInt(str[1]) Integer.parseInt Integer str[1] str 1 int aHP = Integer.parseInt(str[2]); aHP Integer.parseInt(str[2]) Integer.parseInt Integer str[2] str 2 int aATK = Integer.parseInt(str[3]); aATK Integer.parseInt(str[3]) Integer.parseInt Integer str[3] str 3 int count = 0; count 0 for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        } int i = 0; int i = 0; i 0 i < 200 i 200 i++ i++ i {
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        } {
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        } aHP -= tATK aHP tATK count++ count if(aHP <= 0){
                break;
            } aHP <= 0 aHP 0 {
                break;
            } break; tHP -= aATK tHP aATK count++ count if(tHP <= 0){
                break;
            } tHP <= 0 tHP 0 {
                break;
            } break; out.println(count % 2 != 0 ? "Yes" : "No") out.println out count % 2 != 0 ? "Yes" : "No" count % 2 != 0 count % 2 count 2 0 "Yes" "No" out.close() out.close out String[] args args public class Main {
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    }
} Main
import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        
        String[] str = br.readLine().split(" ");
        int tHP = Integer.parseInt(str[0]);
        int tATK = Integer.parseInt(str[1]);
        int aHP = Integer.parseInt(str[2]);
        int aATK = Integer.parseInt(str[3]);
        int count = 0;
        
        for(int i = 0; i < 200; i++){
            aHP -= tATK;
            count++;
            if(aHP <= 0){
                break;
            }
            tHP -= aATK;
            count++;
            if(tHP <= 0){
                break;
            }
        }
        
        out.println(count % 2 != 0 ? "Yes" : "No");
        out.close();
        
    }
}