#!/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 = "!@#$%^&*()-+"
    num = True
    lower = True
    upper = True
    spe = True
    count = 0
    for i in password:
        if numbers.find(i) != -1 and num == True:
            num = False 
        if lower_case.find(i) != -1 and lower == True:
            lower = False
        if upper_case.find(i) != -1 and upper == True:
            upper = False
        if special_characters.find(i) != -1 and spe == True:
            spe = False
    
    if num == True:
        count = count + 1
    if lower == True:
        count = count + 1
    if upper == True:
        count = count + 1    
    if spe == True:
        count = count + 1    
    
    if count + n < 6:
        return 6 - n
    else:
        return count
    
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)