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
s=input()
se=set(s)
if len(se)==len(s):
    print((len(s)//2)+1)
elif len(se)==1:
    print(1)
else:
    l=2
    r=(len(s)//2)+1
    if l==r:
        print(l)
    else:
        index={}
        diff={}
        for i,j in enumerate(s):
            index[j]=index.get(j,[])
            if len(index[j])<1:
                index[j].append(i)
            else:
                diff[j]=max(diff.get(j,0),i-index[j][-1])
                index[j].append(i)
        need=sorted(diff.keys(),key=lambda t:diff[t],reverse=False)
        req=True
        for i in need:
            if len(index[i])>=len(s)//diff[i]:
                print(diff[i])
                req=False
                break
        if req:
            print(r)



