A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward as forward. Examples of numerical palindromes are: 
* 232
* 110011
* 54322345
Complete the function to test if the given number (`num`) **can be rearranged** to form a numerical palindrome or not. Return a boolean (`true` if it can be rearranged to a palindrome, and `false` if it cannot). Return `"Not valid"` if the input is not an integer or is less than 0.
For this kata, single digit numbers are **NOT** considered numerical palindromes.  
## Examples
```
5        =>  false
2121     =>  true
1331     =>  true 
3357665  =>  true 
1294     =>  false 
"109982" =>  "Not valid"
-42      =>  "Not valid"
```
def palindrome(n):
    if not isinstance(n, int) or n<0 : return 'Not valid'
    if n<9 : return False
    n = str(n)
    return sum(n.count(c)%2 for c in set(n))<=1 # only the middle letter migth apear once
def palindrome(n):
    if not isinstance(n, int) or n<0 : return 'Not valid'
    if n<9 : return False
    n = str(n)
    return sum(n.count(c)%2 for c in set(n))<=1 # only the middle letter migth apear once