import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    }
} Main public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) TaskA solver = new TaskA(); solver new TaskA() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    } TaskA public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        } solve {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        } String s = in.next(); s in.next() in.next in String t = in.next(); t in.next() in.next in out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No") out.println out s.equals(t.substring(0, s.length())) ? "Yes" : "No" s.equals(t.substring(0, s.length())) s.equals s t.substring(0, s.length()) t.substring t 0 s.length() s.length s "Yes" "No" int testNumber testNumber Scanner in in PrintWriter out out public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    }
} public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main
{
    public static void main(String[] args)
    {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA
    {
        public void solve(int testNumber, Scanner in, PrintWriter out)
        {
            String s = in.next();
            String t = in.next();
            out.println(s.equals(t.substring(0, s.length())) ? "Yes" : "No");
        }

    }
}

