#!/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
    num, low, upp, special = 1, 1, 1, 1
    for i in password:
        if i in numbers:
            num = 0
        elif i in lower_case:
            low = 0
        elif i in upper_case:
            upp = 0
        elif i in special_characters:
            special = 0
    return max(6 - n, num + low + upp + special)
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)