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.
The first line contains string *s* consisting of lowercase Latin letters (1 ≤ |*s*| ≤ 100000).
none
abacaba
2
zzzzz
1
abcde
3
bcaccacaaabaacaabaaabcbbcbcaacacbcbaaaacccacbbcbaabcbacaacbabacacacaccbbccbcbacbbbbccccabcabaaab
8
daabcdabbabbacacbaacabacbcaabaacac
4
abghim
4
gfliflgfhhdkceacdljgkegmdlhcgkcmlelmbbbmdddgdeeljjhgbbffmemmmkhebgkhadkdajabcjkcgbkgbaeacdedlkklfech
17
a
1
aaabbb
4
ab
2
abbb
2
ob
2
abccba
3
saaaaaaaas
2
axxx
2
abcba
2
abb
2
abcdea
4
axcbb
3
tmivvdcbbfrfogjviirrximhttoskopwrcmkcborcxvr
13
dlchmmuateksgldkckljrovmeuniobjrelqjpnjljlvhpqrjsfklliqpufplgaelevmlcnodbllquubobecem
15
zx
2
zxz
2
bbhdgaefbhf
6
xx
1
zxx
2
cbcada
4
z
1
aab
2
jficc
3
cceeaabfba
5
jk
2
lzeznbwu
5
rr
1
// Author : ps41

#include <bits/stdc++.h>
using namespace std;
#define ll int64_t
const int M = 1e9 + 7, N = 1e6 + 5;

int main()
{
    ios::sync_with_stdio(false), cin.tie(nullptr);
    string s;
    cin >> s;
    int n = s.size();
    int ans = 99999999;
    for (char i = 'a'; i <= 'z'; i++)
    {
        int ind = -1;
        int tmp = 0;
        for (int j = 0; j < n; j++)
        {
            if (s[j] == i)
            {
                int dist = j - ind;
                tmp = max(tmp, dist);
                ind = j;
            }
        }
        tmp = max(tmp, n - ind);
        ans = min(ans, tmp);
    }
    cout << ans;
}