#!/bin/python3

import sys


def need_one(password, chars):
    for c in chars:
        if c in password:
            return False
    return True        


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 = "!@#$%^&*()-+"
    
    need = 0
    need += 1 if need_one(password, numbers) else 0
    need += 1 if need_one(password, lower_case) else 0
    need += 1 if need_one(password, upper_case) else 0
    need += 1 if need_one(password, special_characters) else 0
    
    if len(password)+need<6:
        need += 6-len(password)-need
    #needed_len = max(needed_len, 6)
    return need
    

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