#!/bin/python

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    # Return the minimum number of characters to make the password strong
    
    number, lower, upper, special = False, False, False, False
    result = 0
    
    for c in password:
        if c in numbers:
            number = True
        elif c in lower_case:
            lower = True
        elif c in upper_case:
            upper = True
        elif c in special_characters:
            special = True
    if not number: result += 1
    if not lower: result += 1
    if not upper: result += 1
    if not special: result += 1
    
    if len(password) + result < 6:
        add = 6 - (len(password) + result)
        result += add
    
    return result
    

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