There is an array of strings. All strings contains similar _letters_ except one. Try to find it!
```python
find_uniq([ 'Aa', 'aaa', 'aaaaa', 'BbBb', 'Aaaa', 'AaAaAa', 'a' ]) # => 'BbBb'
find_uniq([ 'abc', 'acb', 'bac', 'foo', 'bca', 'cab', 'cba' ]) # => 'foo'
```
Strings may contain spaces. Spaces is not significant, only non-spaces symbols matters. E.g. string that contains only spaces is like empty string.
It’s guaranteed that array contains more than 3 strings.
This is the second kata in series:
1. [Find the unique number](https://www.codewars.com/kata/585d7d5adb20cf33cb000235)
2. Find the unique string (this kata)
3. [Find The Unique](https://www.codewars.com/kata/5862e0db4f7ab47bed0000e5)
def find_uniq(arr):
    counts = {}
    result = {}
    
    for s in arr:
        hash = frozenset(s.strip().lower())
        counts[hash] = counts.get(hash, 0) + 1
        result[hash] = s
        
        if len(counts) > 1 and counts[max(counts, key=counts.get)] > 1:
            return result[min(counts, key=counts.get)]
def find_uniq(arr):
    counts = {}
    result = {}
    
    for s in arr:
        hash = frozenset(s.strip().lower())
        counts[hash] = counts.get(hash, 0) + 1
        result[hash] = s
        
        if len(counts) > 1 and counts[max(counts, key=counts.get)] > 1:
            return result[min(counts, key=counts.get)]