#!/bin/python3

import sys
import re

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 = "!@#$%^&*()-+"
    count = 0
    if not any((c in numbers) for c in password):
        count = count + 1
        
    if not any((c in lower_case) for c in password):
        count = count + 1
        
    if not any((c in upper_case) for c in password):
        count = count + 1
        
    if not any((c in special_characters) for c in password):
        count = count + 1
    
    if (n + count) >= 6:
        return count
    else:
        return 6-n

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