#!/bin/python

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    has_number = False
    has_lower_case = False
    has_upper_case = False
    has_special = False
    for c in password:
        if c in numbers:
            has_number = True
        if c in lower_case:
            has_lower_case = True
        if c in upper_case:
            has_upper_case = True
        if c in special_characters:
            has_special = True
    res = 0
    if not has_number:
        res += 1
    if not has_lower_case:
        res += 1
    if not has_upper_case:
        res += 1
    if not has_special:
        res += 1
    if n + res < 6:
        res = 6 - n
    return res


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