#!/bin/python3

import sys

numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"
req_num = 6


def minimumNumber(n, password):
    req = 0
    # Return the minimum number of characters to make the password strong
    without_lower = set(password) & set(lower_case)
    if not without_lower:
        req += 1
    without_num = set(password) & set(numbers)
    if not without_num:
        req += 1
    without_upper = set(password) & set(upper_case)
    if not without_upper:
        req += 1
    without_spec = set(password) & set(special_characters)
    if not without_spec:
        req += 1
    
    if n >= 6:
        return req
    return max(6 - n, req)
        

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