#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    num_yn=0
    low_yn=0
    upp_yn=0
    spe_yn=0
    for char in password:
        if char in numbers:
            num_yn=1
        if char in lower_case:
            low_yn=1
        if char in upper_case:
            upp_yn=1
        if char in special_characters:
            spe_yn=1
    mis=4-(num_yn+low_yn+upp_yn+spe_yn)
    if n<6:
        return max(6-n,mis)
    else:
        return mis
    

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