#!/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
    #numSpecial = 0
    numTotal = 0
    numTotal = max(0,6-n)
    lower = True
    upper = True
    numer = True
    special = True
    for n in password:
        if n in numbers:
            numer = False
        elif n in lower_case:
            lower = False
        elif n in upper_case:
            upper = False
        elif n in special_characters:
            special = False
    myArr = [lower,upper,numer,special]
        
    return max(numTotal,sum(myArr))

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