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

public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
            
            String s = br.readLine();
            String t = br.readLine();
            t = t.substring(0, s.length());
            
            PrintWriter pw = new PrintWriter(System.out);
            pw.println((s.equals(t)) ? "Yes" : "No");
            pw.flush();
            
        }
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz