#!/bin/python3

import sys

def minimumNumber(n, password):
    lower = upper = special = dig = False
    add = 0
    for i in password:
        if i in "a b c d e f g h i j k l m n o p q r s t u v w x y z".split():
            lower = True
        elif (i == '!' or i == '@' or i == '#' or i == '$' or i == '%' or i == '^' or i == '&' or i == '*' or i =='(' or i == ')' or i == '-' or i == '+'):
            special = True
        elif i in "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z".split():
            upper = True
        elif i.isdigit():
            dig = True
            
    if lower and special and upper and dig and len(password) >= 6:
        return add
    if not lower:
        add += 1
    if not special:
        add += 1
    if not upper:
        add += 1
    if not dig:
        add += 1
    while(len(password) + add < 6):
        add += 1
    
    return add
        
        

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