#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    count = 0
    for c in numbers:
        if c in password:
            break
    else:
        count += 1
    for c in lower_case:
        if c in password:
            break
    else:
        count += 1
    for c in upper_case:
        if c in password:
            break
    else:
        count += 1  
    for c in special_characters:
        if c in password:
            break
    else:
        count += 1 
    return max(count, 6-n)

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