#!/bin/python

import sys

def minimumNumber(n, password):
    numbers = ['0','1','2','3','4','5','6','7','8','9']
    lower_case = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
    upper_case = ['A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z']
    special_characters = ['!','@','#','$','%','^','&','*','(',')','-','+']
    my_list = list(password)
    count = 0
    if len(set(my_list).intersection(set(numbers))) == 0:
        count += 1
        n += 1
    if len(set(my_list).intersection(set(lower_case))) == 0:
        count += 1
        n += 1
    if len(set(my_list).intersection(set(upper_case))) == 0:
        count += 1
        n += 1
    if len(set(my_list).intersection(set(special_characters))) == 0:
        count += 1
        n += 1
    if n < 6:
        count += (6- n)
    return count
    
                

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