Smallest Substring with Both Characters

Given a string \(S\) consisting of lowercase letters (mainly 'a' and 'b'), find the length of the smallest contiguous substring that contains at least one 'a' and at least one 'b'. If no such substring exists, output 0.

For example, if \(S = \texttt{abba}\), one possible valid substring is "ab" which has a length of 2.

You are required to read the input from standard input (stdin) and output the result to standard output (stdout).

inputFormat

The input consists of a single line that contains a non-empty string \(S\) composed of lowercase English letters.

outputFormat

Output an integer representing the length of the smallest contiguous substring of \(S\) that contains at least one 'a' and one 'b'. If no such substring exists, output 0.

abba

2