#include<iostream>
#include<string>

using namespace std;

int main(){
 string s,y,z;
 cin >> s;
 cin >> y;
 z = s;
 for(int i = 0; i < s.length(); i++)
  for(int j = 0; j < s.length(); j++)
      if(s.at(i) == y.at(j)&&z.at(j)!=y.at(j)){
        z[j] = y[j];
        break;}

if(z==y)
  cout << "YES" << endl;
else
  cout << "NO" <<endl;

return 0;
}