import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class Main {
	static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	}
	
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	}

} import java.io.BufferedReader; BufferedReader java.io import java.io.BufferedWriter; BufferedWriter java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.OutputStreamWriter; OutputStreamWriter java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
	static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	}
	
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	}

} Main public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	} main {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); bw new BufferedWriter(new OutputStreamWriter(System.out)) StringTokenizer st = new StringTokenizer(br.readLine()); st new StringTokenizer(br.readLine()) int A = Integer.parseInt(st.nextToken()); A Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st int B = Integer.parseInt(st.nextToken()); B Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st int C = Integer.parseInt(st.nextToken()); C Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st int D = Integer.parseInt(st.nextToken()); D Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st Monster ta = new Monster(A, B); ta new Monster(A, B) Monster ao = new Monster(C, D); ao new Monster(C, D) while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		} true {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		} ao.health -= ta.strength ao.health ao ao.health ta.strength ta ta.strength if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			} ao.health <= 0 ao.health ao ao.health 0 {
				bw.write("Yes\n");
				break;
			} bw.write("Yes\n") bw.write bw "Yes\n" break; ta.health -= ao.strength ta.health ta ta.health ao.strength ao ao.strength if(ta.health <= 0) {
				bw.write("No\n");
				break;
			} ta.health <= 0 ta.health ta ta.health 0 {
				bw.write("No\n");
				break;
			} bw.write("No\n") bw.write bw "No\n" break; bw.flush() bw.flush bw String[] args args static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	} Monster int health health strength; strength Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		} Monster {
			this.health = health;
			this.strength = strength;
		} this.health = health this.health this this.health health this.strength = strength this.strength this this.strength strength int health health int strength strength public class Main {
	static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	}
	
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	}

} public class Main {
	static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	}
	
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	}

} Main
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class Main {
	static class Monster{
		int health, strength;
		
		Monster(int health, int strength){
			this.health = health;
			this.strength = strength;
		}
	}
	
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
		StringTokenizer st = new StringTokenizer(br.readLine());
		
		int A = Integer.parseInt(st.nextToken());
		int B = Integer.parseInt(st.nextToken());
		int C = Integer.parseInt(st.nextToken());
		int D = Integer.parseInt(st.nextToken());
		
		Monster ta = new Monster(A, B);
		Monster ao = new Monster(C, D);
		
		while(true) {
			ao.health -= ta.strength;
			if(ao.health <= 0) {
				bw.write("Yes\n");
				break;
			}
			
			ta.health -= ao.strength;
			if(ta.health <= 0) {
				bw.write("No\n");
				break;
			}
			
		}
		
		bw.flush();
	}

}
