CF888C.K-Dominant Character

You are given a string s consisting of lowercase Latin letters. Character c is called k-dominant iff each substring of s with length at least k contains this character c.

You have to find minimum k such that there exists at least one k-dominant character.

给你一个由小写拉丁字母组成的字符串 $s$。若字符 $c$ 满足：$s$ 中每个长度至少为 $k$ 的子串都包含该字符 $c$，则称 $c$ 是 $k$-主导的（$k$-dominant）。

你需要找出最小的 $k$，使得至少存在一个 $k$-主导的字符。

The first line contains string s consisting of lowercase Latin letters (1 ≤ |s| ≤ 100000).

第一行包含一个由小写拉丁字母组成的字符串 $s$（$1 \leq |s| \leq 100000$）。

Print one number — the minimum value of k such that there exists at least one k-dominant character.

输出一个数字——满足存在至少一个 k-主导字符的最小 k 值。