#!/bin/python3

import sys

specialcharacters = "!@#$%^&*()-+"

def has_rng_chr(password, lb, ub):
    for char in password:
        if ord(char) in range(lb, ub):
            return True
    return False

def has_number(password):
    return has_rng_chr(password, 48, 58)

def has_uc(password):
    return has_rng_chr(password, 65, 91)

def has_lc(password):
    return has_rng_chr(password, 97, 123)

def has_special(password):
    for char in password:
        if char in "!@#$%^&*()-+":
            return True
    return False

def minimumNumber(n, password):
    missing_types = 4 - (has_number(password) + has_uc(password) + has_lc(password) + has_special(password))
    return max(6-n, missing_types)

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