# Change a Company Tag using algorithms #

print (

"""

There is a Company with a Tag comment (string) that when we divide the

comment into equal sub strings - All are supposed to be equal

However we have incorrect Tags assigned to the company which we need

to change.

The Task is:

for a given Tag comment we need to check that all the sub-strings are equal

if not, we need to change the sub-strings so that all will be same

in such a way that the cost of doing this operation is minimum

The cost of changing a to b is 1 which is difference between the

locations of a and b in alphabets

Example: Given string -> aabaaabab, K = 3,

aab | aaa | bab

The cost is equal to a->b + b->a i.e 1+1 = 2

result : aab | aab | aab (All are equal)

"""

)

import string

import numpy as np

STRG = input()

k = int(input())

alphabs = list(string.ascii_lowercase)

costs = [alphabs.index(i)+1 for i in alphabs]

CHARS = len(alphabs)

def correction_strg(strg,K):

return

x = correction_strg(STRG,k)

print (min(x[0]))