import sys

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

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    min_ = 0
    plus = 1
    for char in numbers:
        if char in password:
            plus = 0
    min_ += plus
    plus = 1
    for char in lower_case:
        if char in password:
            plus = 0
    min_ += plus
    plus = 1
    for char in upper_case:
        if char in password:
            plus = 0
    min_ += plus
    plus = 1
    for char in special_characters:
        if char in password:
            plus = 0
    min_ += plus
    if min_ + len(password) < 6:
        min_ += 6-  (min_ + len(password))
    return min_
if __name__ == "__main__":
    n = int(raw_input().strip())
    password = raw_input().strip()
    answer = minimumNumber(n, password)
    print answer