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

int main() {
    char a[11], b[11];
    int f[26]={0};
    
    scanf("%s%s", a, b);
    
    if (strlen(a) != strlen(b)) {
        printf("Invalid input");
        return 0;
    }
    
    for (int i = 0; a[i]; i++) {
        if (!isalpha(a[i]) || !salpha(b[i])) {
            printf("Invalid input");
            return 0;
        }
        
        f[a[i]-'a']++;
        f[b[i]-'a']--;
    }
    
    for (int i = 0; i < 26; i++)
        if (f[i]) {
            printf("No");
            return 0;
        } 
        printf("YES");
        return 0;
}