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
#include <bits/stdc++.h>


using namespace std;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	string s; cin >> s;
	vector<int> reg(500, -1), maxim(500, -1);

	for(int i=0; i<s.size(); ++i) {
		maxim[s[i]] = max(maxim[s[i]], i - reg[s[i]]);
		reg[s[i]] = i;
	}

	int res = 1e9;
	for(char c = 'a'; c <= 'z'; ++c) {
		if(reg[c] == -1) 
			continue;

		res = min(res, max(maxim[c], ((int) s.size() - reg[c])));
	}

	cout << res << "\n";


	return 0;
}