#!/bin/python3

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    # Return the minimum number of characters to make the password strong
    req=0
    if not any(ch in numbers for ch in password):req+=1
    if not any(ch in lower_case for ch in password):req+=1
    if not any(ch in upper_case for ch in password):req+=1
    if not any(ch in special_characters for ch in password):req+=1
    if len(password)+req<6:req+=6-len(password)-req
    return req

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