#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    
    numbers = "0123456789" # Need one from here
    lower_case = "abcdefghijklmnopqrstuvwxyz" # Need one from here
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" # Need one from here
    special_characters = "!@#$%^&*()-+" # Need one from here

    min_num_to_add = 0
    StrongFlags = [1, 1, 1, 1]
    
    if len(password) == 0:
        return 6
    else:
        for c in password:
            if c in numbers:
                StrongFlags[0] = 0
            elif c in lower_case:
                StrongFlags[1] = 0
            elif c in upper_case:
                StrongFlags[2] = 0
            elif c in special_characters:
                StrongFlags[3] = 0
         
        if len(password) >= 6:
            return sum(StrongFlags)
        else:
            return max(sum(StrongFlags), 6 - len(password))
        
        
    
    
    

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