#!/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 = "!@#$%^&*()-+"
    count = 0
    if (len(list(set(list(password)).intersection(list(numbers)))) == 0):
        count+=1
    if (len(list(set(list(password)).intersection(list(lower_case)))) == 0):
        count+=1
    if (len(list(set(list(password)).intersection(list(upper_case)))) == 0):
        count+=1
    if (len(list(set(list(password)).intersection(list(special_characters)))) == 0):
        count+=1
    if(len(password)+count<6):
        count += (6 - (len(password)+count))
    return count
    

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