#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    modsneeded = 0
    if sum(1 for c in password if c in '0123456789') < 1:
        modsneeded += 1
    if sum(1 for c in password if c in 'abcdefghijklmnopqrstuvwxyz') < 1:
        modsneeded += 1
    if sum(1 for c in password if c in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ') < 1:
        modsneeded += 1
    if sum(1 for c in password if c in '!@#$%^&*()-+') < 1:
        modsneeded += 1
    if n + modsneeded < 6:
        modsneeded = 6 - n
    return modsneeded

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