#!/bin/python3

import sys

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

def minimumNumber(n, password):
    add=0
    pa=set(password)
    if pa.intersection(numbers)==set():
        add+=1
    if pa.intersection(lower_case)==set():
        add+=1
    if pa.intersection(upper_case)==set():
        add+=1
    if pa.intersection(special_characters)==set():
        add+=1
    if len(password)+add<6:
        return 6-len(password)
    else:
        return add
    # Return the minimum number of characters to make the password strong

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