#!/bin/python

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    res = 0
    if not any(map(lambda x: x in lower_case, password)):
        res = res + 1
    if not any(map(lambda x: x in numbers, password)):
        res = res + 1
    if not any(map(lambda x: x in upper_case, password)):
        res = res + 1
    if not any(map(lambda x: x in special_characters, password)):
        res = res + 1
    return res + max(0,(6 - (n + res)))
if __name__ == "__main__":
    n = int(raw_input().strip())
    password = raw_input().strip()
    answer = minimumNumber(n, password)
    print answer