#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define all(x) (x).begin(),(x).end()
typedef long long ll;
// #include<C:\Users\J\Desktop\AC\athead.h>
#define showa(v) for(int iii = 0; iii < v.size(); iii++){ cout << v[iii] << " ";} cout << endl;
#define show(iiii) cout << iiii << endl; 
#define shows(iiiii) cout << iiiii << " ";
#include<iostream>
#include<string>
#include<vector>
#include<stdio.h>
#include <cmath>
#include <cstdlib>
#include <cassert>
#include <algorithm>
#include <set>
#include <deque>
#include <numeric>
#include<tuple>
#include <utility>
#include <map>
#include<stack>
#include<queue>
#include <cassert>
using namespace std;

 
int main(){
    string s, t;
    cin >> s >> t;
    bool flag=true;
    for(int i=0; i<s.size(); i++){
        if(s[i] != t[i]){
            flag = false;
            break;
        }        
    }
    if(flag) cout << "Yes" << endl;
    else  cout << "No" << endl;
}