import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int tHP = sc.nextInt(); tHP sc.nextInt() sc.nextInt sc int tAtack = sc.nextInt(); tAtack sc.nextInt() sc.nextInt sc int aHP = sc.nextInt(); aHP sc.nextInt() sc.nextInt sc int aAtack = sc.nextInt(); aAtack sc.nextInt() sc.nextInt sc boolean isTkhsWin = false; isTkhsWin false while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        } true {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        } aHP -= tAtack aHP tAtack if (aHP <= 0) {
                isTkhsWin = true;
                break;
            } aHP <= 0 aHP 0 {
                isTkhsWin = true;
                break;
            } isTkhsWin = true isTkhsWin true break; tHP -= aAtack tHP aAtack if (tHP <= 0) {
                isTkhsWin = false;
                break;
            } tHP <= 0 tHP 0 {
                isTkhsWin = false;
                break;
            } isTkhsWin = false isTkhsWin false break; String result = isTkhsWin ? "Yes" : "No"; result isTkhsWin ? "Yes" : "No" isTkhsWin "Yes" "No" 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){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int tHP = sc.nextInt();
        int tAtack = sc.nextInt();
        int aHP = sc.nextInt();
        int aAtack = sc.nextInt();
        boolean isTkhsWin = false;

        while(true) {
            // 高橋の攻撃
            aHP -= tAtack;
            if (aHP <= 0) {
                isTkhsWin = true;
                break;
            }
            // 青木の攻撃
            tHP -= aAtack;
            if (tHP <= 0) {
                isTkhsWin = false;
                break;
            }
        }
        String result = isTkhsWin ? "Yes" : "No";
        System.out.println(result);
    }
}