import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    }
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    }
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    } main {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc String T = sc.next(); T sc.next() sc.next sc if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No"); S.substring(0,S.length()).equals(T.substring(0,S.length())) S.substring(0,S.length()).equals S.substring(0,S.length()) S.substring S 0 S.length() S.length S T.substring(0,S.length()) T.substring T 0 S.length() S.length S {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		} if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No"); T.substring(T.length()) != "" T.substring(T.length()) T.substring T T.length() T.length T "" {
				System.out.print("Yes");
			} System.out.print("Yes") System.out.print System.out System System.out "Yes" System.out.print("No") System.out.print System.out System System.out "No" System.out.print("No") System.out.print System.out System System.out "No" String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    }
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    }
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String T = sc.next();

		if(S.substring(0,S.length()).equals(T.substring(0,S.length()))) {
			if(T.substring(T.length()) != "") {
				System.out.print("Yes");
			}
			else
				System.out.print("No");
		}
		else
			System.out.print("No");

    }
}
