import java.util.*;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String a = sc.next();
      String b = sc.next();
      int flag = 0;
      char []x =a.toCharArray();
      char []y =b.toCharArray();
      for(int i=0;i<x.length;i++){
        if(x[i]!=y[i]){
          flag = 1;
          break;
        }
      }
      if(flag==0){
        System.out.println("Yes");
      }
      else{
        System.out.println("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