#!/bin/python

import sys

def number_check(password):
    numbers = "0123456789"
    num_check = 1
    for i in numbers:
        if i in password:
            num_check = 0
    return num_check

def lower_check(password):
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    low_check = 1
    for i in lower_case:
        if i in password:
            low_check = 0
    return low_check

def upper_check(password):
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    up_check = 1
    for i in upper_case:
        if i in password:
            up_check = 0
    return up_check

def char_check(password):
    special_characters = "!@#$%^&*()-+"
    ch_check = 1
    for i in special_characters:
        if i in password:
            ch_check = 0
    return ch_check

def minimumNumber(n, password):
    len_check =0
    if n < 6:
        len_check = 6-n
    num_check = number_check(password)
    low_check = lower_check(password)
    up_check = upper_check(password)
    ch_check = char_check(password)
    if len_check > num_check+low_check+up_check+ch_check:
        return len_check
    else:
        return num_check+low_check+up_check+ch_check

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