#include <bits/stdc++.h>
using namespace std;
typedef pair <int,int> PII;
typedef long long int LL;
#define REP(i,j)      for(int i=0;i<j;i++)
#define REPNM(i,j,k)  for(int i=j;i<k;i++)
#define RREP(i,j,k)   for(int i=j;i>=k;i--)
#define pb   push_back
#define mp   make_pair
#define A    first
#define B    second
#define MEM(i,j)      memset(i,j,sizeof i)
#define ALL(i)        i.begin(),i.end()
#define DB()          if(debug)
#define DBGG(i,j)     DB()cout<<i<<" "<<j<<endl;
#define DB4(i,j,k,l)  DB() cout<<i<<" "<<j<<" "<<k<<" "<<l<<endl;
#define RI(i)       scanf("%d",&i)
#define RII(i,j)    RI(i) , RI(j)
#define RIII(i,j,k) RII(i , j) , RI(k)
#define RL(i)       scanf("%lld",&i)
#define RLL(i,j)    RL(i) , RL(j)
#define RLLL(i,j,k) RLL(i , j) , RL(k)
///---------------------------
#define MAX 201
#define INF 0x3f3f3f3f
#define debug 1
#define MOD 1000000007LL

string a , b;

int solve(int la , int ra , int lb , int rb){
	int len = ra - la + 1;
	int ok = 1;
	REP(i , len){
		if(a[la + i] != b[lb + i]){
			ok = 0; break;
		}
	}
	if(ok)return 1;
	if(len & 1) return 0;
	int use[30];
	MEM(use , 0);
	REP(i , len){
		use[ a[la + i] - 'a' ]++;
		use[ b[lb + i] - 'a' ]--;
	}
	REP(i , 30) if(use[i] != 0)return 0;

	int ha = len / 2;
	int aa = la + ha - 1;
	int bb = lb + ha - 1;

	if(solve(la , aa , lb , bb) == 1 && solve(aa + 1 , ra , bb + 1 , rb) == 1)return 1;
	if(solve(la , aa , bb + 1 , rb) == 1 && solve(aa + 1 , ra , lb , bb) == 1)return 1;
	return 0;
}

int main(){
	cin.tie(0) , cout.sync_with_stdio(0);
	while(cin >> a >> b){
		int len = a.size();
		int ok = solve(0 , len - 1 , 0 , len - 1);
		if(ok)cout << "YES" << endl;
		else cout << "NO" << endl;
	}
    return 0;
}