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 countArr(arr):
    count = 0
    for ele in arr:
        if ele != 0:
            count += 1
    return count
def main():
    # t = int(input())
    for case in range(1):
        S = input()

        low = 0
        high = len(S)
        ans = high
        n = len(S)
        while low <= high:
            freqArr = []
            mid = (low + high) // 2
            for i in range(n - mid + 1):
                arr = S[i:i+mid]
                freq = [0] * 26
                for ele in arr:
                    freq[ord(ele) - 97] = 1
                freqArr.append(freq)
            temp = [1] * 26
            for ele in freqArr:
                for j in range(26):
                    temp[j] = temp[j] & ele[j]

            count = countArr(temp)
            if count != 0:
                ans = mid
                high = mid - 1
            else:
                low = mid + 1

        print(ans)

if __name__ == '__main__':
    main()
