https://www.hackerrank.com/challenges/re-group-groups
group()
A group() expression returns one or more subgroups of the match.
groups()
A groups() expression returns a tuple containing all the subgroups of the match.
groupdict()
A groupdict() expression returns a dictionary containing all the named subgroups of the match, keyed by the subgroup name.
Task
You are given a string S.
Your task is to find the first occurrence of an alphanumeric character in S (read from left to right) that has consecutive repetitions.
Input format
A single line of input containing the string S.
Output Format
Print the first occurrence of the repeating character. If there are no repeating characters, print -1.
Sample Input 0
..12345678910111213141516171820212223
Sample Output 0
1