import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    least = 6
    enough = False
    total = 0
    sub_total = 0

    if n < least:
        enough = True
        total = (least - n)

    if not (any(password[i] in numbers for i in range(len(password)))):
        if enough:
            sub_total += 1
        else:
            total += 1
    
    if not (any(password[i] in lower_case for i in range(len(password)))):
        if enough:
            sub_total += 1
        else:
            total += 1

    if not (any(password[i] in upper_case for i in range(len(password)))):
        if enough:
            sub_total += 1
        else:
            total += 1

    if not (any(password[i] in special_characters for i in range(len(password)))):
        if enough:
            sub_total += 1
        else:
            total += 1

    if enough and sub_total > total:
        return sub_total
    else:
        return total

if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)