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
def main():
    s = input()
    lo, hi = 0, len(s)
    while lo + 1 < hi:
        mid = (lo + hi) // 2
        cnt = dict.fromkeys("abcdefghijklmnopqrstuvwxyz", 0)
        for i in range(mid):
            cnt[s[i]] += 1
        v = {c for c, x in cnt.items() if not x}
        for i, c in zip(range(mid, len(s)), s):
            cnt[s[i]] += 1
            cnt[c] -= 1
            if not cnt[c]:
                v.add(c)
        if len(v) < 26:
            hi = mid - 1
        else:
            lo = mid
    print(lo + 1)


if __name__ == '__main__':
    main()
