#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    special = 4
    if (any(elem in password for elem in numbers)): special -= 1
    if (any(elem in password for elem in lower_case)): special -= 1
    if (any(elem in password for elem in upper_case)): special -= 1
    if (any(elem in password for elem in special_characters)): special -= 1
    return(max(0 if len(password) > 6 else 6-len(password), special))

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