#!/bin/python3

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
    upper = False
    lower = False
    digit = False
    special = False
    out = 0
    for c in password:
        if(c in numbers):
            digit = True
        if(c in lower_case):
            lower = True
        if(c in upper_case):
            upper = True
        if(c in special_characters):
            special = True
    if(not digit):
        out += 1
    if(not lower):
        out += 1
    if(not upper):
        out += 1
    if(not special):
        out += 1
    if(n + out < 6):
        out = 6-n
    return out

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