#!/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
    length = 4
    for i in numbers:
        if i in password:
            length -= 1
            break
    for i in lower_case:
        if i in password:
            length -= 1
            break
    for i in upper_case:
        if i in password:
            length -= 1
            break
    for i in special_characters:
        if i in password:
            length -= 1
            break
    temp = len(password)
    #print(length, temp)
    if 6 >= temp:
        return max(length, (6 - temp))
    else:
        return length

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