#!/bin/python3

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    count = 4 
    flagN,flagL,flagU,flagS = 0,0,0,0
    for char in password:
        if count == 0:
            break
        if char in numbers and flagN == 0:
            count -= 1
            flagN = 1
            continue
        if char in lower_case and flagL == 0:
            count -= 1
            flagL = 1
            continue
        if char in upper_case and flagU == 0:
            flagU = 1
            count -= 1
            continue
        if char in special_characters and flagS == 0:
            flagS = 1
            count -= 1
            continue
    if n < 6:
        if count < 6 - n:
            return 6-n
        else:
            return count
    return count
    
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)