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

void quick_sort(char *str, int left, int right);
void change(char &a, char &b);

int main(void)
{
	char a[11], b[11];
	scanf("%s %s", a, b);
	int n; n = (int)strlen(a);

	quick_sort(a, 0, n-1); 
	quick_sort(b, 0, n-1);

	if (strcmp(a, b) == 0) { 
		printf("YES\n");
	} else {
		printf("NO\n");
	}

	return 0;
}

void quick_sort(char *str, int left, int right)
{
	if (left >= right) return;

	int p = left, k = left+1;

	while (k <= right) {

		if ((int)str[left] > (int)str[k]) {
			change(str[p+1], str[k]);
			p++;
		}
		k++;
	}
	change(str[left], str[p]);

	quick_sort(str, left, p-1);
	quick_sort(str, p+1, right);
}

void change(char &a, char &b)
{
	char temp;
	temp = a;
	a = b;
	b = temp;
}