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));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	}
} 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));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	}
} Main public static void main(String[] args) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	} main {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    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 s = br.readLine().trim(); s br.readLine().trim() br.readLine().trim br.readLine() br.readLine br String t = br.readLine().trim(); t br.readLine().trim() br.readLine().trim br.readLine() br.readLine br if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		} s.equals(t.substring(0, t.length()-1)) s.equals s t.substring(0, t.length()-1) t.substring t 0 t.length()-1 t.length() t.length t 1 {
		    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 public class Main
{
	public static void main(String[] args) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	}
} public class Main
{
	public static void main(String[] args) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	}
} 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));
		String s = br.readLine().trim();
		String t = br.readLine().trim();
		if(s.equals(t.substring(0, t.length()-1))){
		    System.out.println("Yes");
		}
		else{
		    System.out.println("No");
		}
	}
}
