#!/bin/python3

import sys
numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"
def minimumNumber(n, password):
    count = 0
    special_characters_no = 0
    numbers_no = 0
    lower_case_no = 0
    upper_case_no = 0
    for i in password:
        if i in special_characters:
            special_characters_no += 1
        elif i in lower_case:
            lower_case_no += 1
        elif i in upper_case:
            upper_case_no += 1
        elif i in numbers:
            numbers_no += 1
    
    if special_characters_no == 0:
        count += 1
    if numbers_no == 0:
        count += 1
    if upper_case_no == 0:
        count += 1
    if lower_case_no == 0:
        count += 1
    #print(count)
    if n >= 6:
        return count
    elif count+n < 6:
        return count+6-(count+n)
    elif count+n >= 6:
        return count
            

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