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
import sys
input = sys.stdin.readline
a = input().strip() #k-domin
let = {}
for i in a:
    if i not in let:
        let[i]=1
    else:
        let[i]+=1
let = sorted(let.items(),key=lambda item:item[1],reverse=True)
k = 0
kk = 0
minn = 1e9
for i in let:
    f=0
    n=0
    for c in range(1,len(a)+1):
        for l in range(len(a)-c):
            n+=1
            if a[l:l+c].count(i[0])>=1:
                f+=1
        n+=1
        if a[l+1:l+c+1].count(i[0])>=1:
            f+=1
        if f==n:
            minn =min(minn,c)
        n = 0
        f = 0
print(minn)


