#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int main(int argc, char const* argv[]) {
    string a, b;

    cin >> a >> b;

    bool a_eq_b_flag = true;
    string::iterator a_itr = a.begin();
    for (int i = 0; i < b.size(); i++) {
        string::iterator a_judge = find(a_itr, a.end(), b[i]);
        if (a_judge == a.end()) {
            a_eq_b_flag = false;
            break;
        } else {
            char tmp;
            tmp      = a[i];
            a[i]     = *a_judge;
            *a_judge = tmp;
            a_itr++;
        }
    }

    if (a_eq_b_flag) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }

    return 0;
}