#!/bin/python

import sys

def minimumNumber(n, password):
    a = 0
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    for s in [numbers, lower_case, upper_case, special_characters]:
        contains = False
        for c in s:
            if c in password:
                contains = True
                break
        if not contains:
            a += 1
    if n + a < 6:
        a += (6 - (n + a))
    return a

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