#!/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 = "!@#$%^&*()-+"
    
    extra = 0
    
    if set(password).isdisjoint(numbers):
        extra += 1
    if set(password).isdisjoint(lower_case):
        extra += 1
    if set(password).isdisjoint(upper_case):
        extra += 1
    if set(password).isdisjoint(special_characters):
        extra += 1
        
    if n+extra < 6:
        extra += 6-(n+extra)
    
    return extra

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