#!/bin/python
"""
Its length is > 6.
It contains at least one digit.
It contains at least one lowercase English character.
It contains at least one uppercase English character.
It contains at least one special character. The special characters are: !@#$%^&*()-+
"""
import sys
numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"


def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    strong_counter = 0
    
    if not(set(numbers).intersection(password)):
        strong_counter += 1
    if not(set(lower_case).intersection(password)):
        strong_counter += 1 
    if not(set(upper_case).intersection(password)):
        strong_counter += 1 
    if not(set(special_characters).intersection(password)):
        strong_counter += 1 
        
    if (n + strong_counter) < 6:
        more_ch = 6 - (n+strong_counter)
        strong_counter += more_ch
       
    return strong_counter
        

            
        
    

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