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

class Main {

    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        
        String s = sc.next();
        String t = sc.next();

        if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }

    }

    static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;
    
        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }
    
        int nextInt() {
            return Integer.parseInt(next());
        }
    
        long nextLong() {
            return Long.parseLong(next());
        }
    }
} import java.io.*; io.* java import java.util.*; util.* java class Main {

    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        
        String s = sc.next();
        String t = sc.next();

        if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }

    }

    static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;
    
        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }
    
        int nextInt() {
            return Integer.parseInt(next());
        }
    
        long nextLong() {
            return Long.parseLong(next());
        }
    }
} Main public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        
        String s = sc.next();
        String t = sc.next();

        if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }

    } main {
        MyScanner sc = new MyScanner();
        
        String s = sc.next();
        String t = sc.next();

        if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }

    } MyScanner sc = new MyScanner(); sc new MyScanner() String s = sc.next(); s sc.next() sc.next sc String t = sc.next(); t sc.next() sc.next sc if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        } t.startsWith(s) t.startsWith t s {
            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 static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;
    
        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }
    
        int nextInt() {
            return Integer.parseInt(next());
        }
    
        long nextLong() {
            return Long.parseLong(next());
        }
    } MyScanner BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15); reader new BufferedReader(new InputStreamReader(System.in), 1 << 15) StringTokenizer tokenizer; tokenizer String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        } next {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        } try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            } catch (IOException ignored) {
            } IOException ignored {
            } {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
                    tokenizer = new StringTokenizer(reader.readLine());
                } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer int nextInt() {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong() {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next
import java.io.*;
import java.util.*;

class Main {

    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        
        String s = sc.next();
        String t = sc.next();

        if(t.startsWith(s)){
            System.out.println("Yes");
        }
        else{
            System.out.println("No");
        }

    }

    static class MyScanner {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in), 1 << 15);
        StringTokenizer tokenizer;
    
        String next() {
            try {
                while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                    tokenizer = new StringTokenizer(reader.readLine());
                }
            } catch (IOException ignored) {
            }
            return tokenizer.nextToken();
        }
    
        int nextInt() {
            return Integer.parseInt(next());
        }
    
        long nextLong() {
            return Long.parseLong(next());
        }
    }
}