#!/bin/python

import sys

special_characters = map(ord,list("!@#$%^&*()-+"))


def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    len_add = max(6-n, 0)
    asc_code = map(ord, password)
    # check numbers
    number_count = len([c for c in asc_code if c>=48 and c<=57])
    # check upper
    upper_count = len([c for c in asc_code if c>=65 and c<=90])
    # check lower
    lower_count = len([c for c in asc_code if c>=97 and c<=122])
    # check special 
    special_count = len([c for c in asc_code if c in special_characters])
    char_add = 0 + 1*(number_count==0) + 1*(upper_count==0) + 1*(lower_count==0) + 1*(special_count==0)
    #print number_count, upper_count, lower_count, special_count
    #print char_add, len_add
    return max(char_add, len_add)
    
if __name__ == "__main__":
    n = int(raw_input().strip())
    password = raw_input().strip()
    answer = minimumNumber(n, password)
    print answer