#!/bin/python3

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    password1 = password
    num_ok = False
    low_ok = False
    up_ok = False
    sp_ok = False
    n1 = 0
    for i in range(0,n):
        if password1[i] in numbers:
            num_ok = True
        elif password1[i] in lower_case:
            low_ok = True
        elif password1[i] in upper_case:
            up_ok = True
        elif password1[i] in special_characters:
            sp_ok = True
    
    if num_ok and low_ok and up_ok and sp_ok and (len(password1) >= 6):
        return 0

    if num_ok == False:
        n1 = n1 +1
    if low_ok == False:
        n1 = n1+1
              
    if up_ok == False:
        n1 = n1+1
                
    if sp_ok == False:
                n1 = n1+1
    
    if (n1+n)< 6:
        n1 += (6-(n1+n))
        
    return n1
    # Return the minimum number of characters to make the password strong

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