import java.util.*;
public class Main{
	public static void main(String[] args)
	{
		Scanner in=new Scanner(System.in);
		String s=in.nextLine();
		String t=in.nextLine();
		boolean flag=true;
		for(int i=0;i<s.length();i++)
		{
			if(s.charAt(i)!=t.charAt(i))
				flag=false;
		}
		System.out.println((flag?("Yes"):("No")));
	}
}
/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