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 = "!@#$%^&*()-+" 
    num = 0
    if len(set(numbers) & set(password)) == 0:
        num+=1
    if len(set(lower_case) & set(password)) == 0:
        num+=1
    if len(set(upper_case) & set(password)) == 0:
        num+=1
    if len(set(special_characters) & set(password)) == 0:
        num+=1
    if n + num < 6:
        num += 6 - num - n
    return num