#!/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
    hasDigit = False
    hasLower = False
    hasUpper = False
    hasSpecial = False
    for c in password:
        if hasDigit == False and c in numbers:
            hasDigit = True
        if hasLower == False and c in lower_case:
            hasLower = True
        if hasUpper == False and c in upper_case:
            hasUpper = True
        if hasSpecial == False and c in special_characters:
            hasSpecial = True
        if hasDigit and hasLower and hasUpper and hasSpecial:
            break
    res = 0
    if hasDigit == False:
        res += 1
    if hasLower == False:
        res += 1
    if hasUpper == False:
        res += 1
    if hasSpecial == False:
        res += 1
    if n + res < 6:
        return 6 - n
    return res

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