#!/bin/python3

import sys

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


def contains(s, symbols):
	for c in s:
		if c in symbols:
			return True
	return False

def minimumNumber(n, s):
	res = 0
	if not contains(s, numbers):
		res += 1
	if not contains(s, lower_case):
		res += 1
	if not contains(s, upper_case):
		res += 1
	if not contains(s, special_characters):
		res += 1

	if (len(s) + res) < 6:
		res += 6 - (len(s)+res)

	return res

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