#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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