#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int separa (char *str1, char *str2, int tam){
    if(!strncmp(str1, str2, tam))
        return 1; /* ok = 1, entao sao iguais */
    else if(tam & 1)
        return 0; /* ok = 0, entao sao diferentes */
    else if(separa(str1, str2+tam/2, tam/2) && separa(str1+tam/2, str2, tam/2) || separa(str1, str2, tam/2) && separa(str1+tam/2, str2+tam/2, tam/2))
        return 1;
    else
        return 0;
}

int main() {
    int tam, ok;
    char *str1, *str2;

    scanf("%d", &tam);
        str1 = (char *)malloc (tam*sizeof(char));
        str2 = (char *)malloc (tam*sizeof(char));

    while(tam != 0){
        str1 = (char *)realloc (str1, tam*sizeof(char));
        str2 = (char *)realloc (str2, tam*sizeof(char));

        scanf("%s", str1);
        scanf("%s", str2);

        ok = separa(str1, str2, tam);

        if (!ok){
            printf("NAO\n");
        }
        else {
            printf ("SIM\n");
        }
        scanf("%d", &tam);
    }

    free(str1);
    free(str2);
    return 0;
}