Same Letter Pattern

The words "egg" and "add" have the same shape: a letter, then a different letter that is repeated. Two strings follow the same pattern when you can turn one into the other by swapping characters consistently: every copy of a character is replaced by the same character, and two different characters are never replaced by the same one.

Write same_pattern(a, b) that returns True if a and b follow the same pattern and False otherwise.

Examples

same_pattern('egg', 'add')      # returns True
same_pattern('paper', 'title')  # returns True
same_pattern('foo', 'bar')      # returns False
same_pattern('ab', 'aa')        # returns False

In the last example both "a" and "b" would have to turn into "a", which is not allowed.

Constraints

• 0 <= len(a), len(b) <= 100,000
• The strings may hold any characters. Upper and lower case letters are different characters.