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

int cmp(const void *a, const void *b)
{
    return *(int*)b - *(int*)a;
}

int main()
{
    char a[11] = {-1};
    char b[11] = {-1};
    
    std::cin >> a >> b;
    
    qsort(a,11,1,cmp);
    qsort(b,11,1,cmp);
    
    
    std::cout << ((strcmp(a, b))? "NO":"YES") << std::endl;
    
    return 0;
}