#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    minLength = 6
    toAdd = 0
    toAdd2 = 0
    if minLength > len(password):
        toAdd += minLength-len(password)
    if not any(a for a in numbers if a in password):
        toAdd2 += 1
    if not any(a for a in lower_case if a in password):
        toAdd2 += 1
    if not any(a for a in upper_case if a in password):
        toAdd2 += 1
    if not any(a for a in special_characters if a in password):
        toAdd2 += 1
    return(max(toAdd,toAdd2))

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