#!/bin/python3

import sys

numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"

def minimumNumber(n, password):
    mn = 0
    ml = 0
    mu = 0
    ms = 0
    count = 0
    # Return the minimum number of characters to make the password strong
    if not set.intersection(set(numbers),set(password)):
        mn = 1
        count += 1
    if not set.intersection(set(lower_case),set(password)):
        ml = 1
        count += 1
    if not set.intersection(set(upper_case),set(password)):
        mu = 1
        count += 1
    if not set.intersection(set(special_characters),set(password)):
        ms = 1 
        count += 1
    
    lenPwd = len(password)
    if lenPwd < 6:
        if count < (6-lenPwd):
            count = count + (6-lenPwd-count)
            
    return count
    

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