#!/bin/python3

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

    k = sum([int(not any([c in l for c in password])) for l in [numbers, lower_case, upper_case, special_characters]])
    if n + k < 6:
        return 6 - n
    return k

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