#include <bits/stdc++.h>
using namespace std;
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
 
    string x, y;
    while ( (cin >> x >> y) ) {
        if (y.size() < x.size()) {
            cout << "NO\n";
            continue;
        }
 
        while (y.size() > x.size()) {
            if (y.back() == 'A') {
                y.pop_back();
            } else if (y.front() == 'B') {
                y.erase(y.begin());
                reverse(y.begin(), y.end());
            } else {
                break;
            }
        }
        cout << (y == x ? "YES\n" : "NO\n");
    }
    return 0;
}

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A BABA
A ABBA
BAAAAABAA BAABAAAAAB