#!/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
    add = 0
    if not(any([i in password for i in numbers])):
        add += 1
    if not(any([i in password for i in lower_case])):
        add += 1
    if not(any([i in password for i in upper_case])):
        add += 1
    if not(any([i in password for i in special_characters])):
        add += 1
    if n + add < 6:
        return 6 - n
    return add

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