#include<bits/stdc++.h>
using namespace std;

int main(){
    string A,B;
    cin >> A >> B;

    while(!A.empty()){
        if(B.find(A.back())!=string::npos) B.erase(B.begin()+B.find(A.back()));
        else{
            cout << "NO" << endl;
            return 0;
        }
        A.pop_back();
    }
    cout << "YES" << endl;

    return 0;
}