#!/bin/python3

import sys

def minimumNumber(n, password):
    count=0
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    list (numbers)
    list (lower_case)
    list (upper_case)
    list (special_characters)
    if not any ( x in numbers for x in password ):
        n=n+1
        count+=1
    if not any ( a in lower_case for a in password):
        n=n+1
        count+=1
    if not any ( b in upper_case for b in password):
        n=n+1
        count+=1
    if not any ( c in special_characters for c in password):
        n=n+1
        count+=1
    if n <= 6 :
        count+= 6-n
    return count

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