#!/bin/python3

import sys

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

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    low, up, dig, spec = 0,0,0,0
    for x in password:
        if x in numbers:
            dig += 1
        if x in lower_case:
            low += 1
        if x in upper_case:
            up += 1
        if x in special_characters:
            spec += 1
    letters_need = 0
    if dig == 0:
        letters_need += 1
    if low == 0:
        letters_need += 1
    if up == 0:
        letters_need += 1
    if spec == 0:
        letters_need += 1
    
    if n + letters_need < 6:
        letters_need = 6 - n
        
    return letters_need
        

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