n = int(input())
password = raw_input()

numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"

missing_length = 6-n
number_missing = 1
lower_missing = 1
upper_missing = 1
special_missing = 1

for ele in password:
    if ele in numbers:
        number_missing = 0
    if ele in lower_case:
        lower_missing = 0
    if ele in upper_case:
        upper_missing = 0
    if ele in special_characters:
        special_missing = 0
 
print max(number_missing+lower_missing+upper_missing+special_missing,missing_length)