#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <map>
using namespace std;

class Conversion {
  public:
    string Y;
    int Reachable(string X);
    map <string, int> Cache;
};

int Conversion::Reachable(string X)
{
  string rev;
  int i;

  if (X == Y) return 1;
  if (X.size() <= Y.size()) return 0;

  if (Cache.find(X) != Cache.end()) return Cache[X];

  if (X[X.size()-1] == 'A') {
    if (Reachable(X.substr(0,X.size()-1))) return 1;
  }

  if (X[0] == 'B') {
    for (i = X.size()-1; i > 0; i--) rev.push_back(X[i]);
    if (Reachable(rev)) return 1;
  }
  Cache[X] = 0;
  return 0;
}

int main(int argc, char **argv)
{
  Conversion c;
  int ans;

  if (argc != 3) { fprintf(stderr, "usage: a.out X Y\n"); exit(1); }
  c.Y = argv[2];
  ans = c.Reachable(argv[1]);
  printf("%s\n", (ans) ? "Yes" : "No");
}