#!/bin/python3

import sys

def minimumNumber(n, password):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    addPos = {'useNumbers':1,'useLower':1,'useUpper':1,'useSpec':1}
    
    for char in password:
        if char in numbers: addPos['useNumbers'] = 0
        if char in lower_case: addPos['useLower'] = 0
        if char in upper_case: addPos['useUpper'] = 0
        if char in special_characters: addPos['useSpec'] = 0
    
    sum = 0
    for val in addPos: sum += addPos[val] 
        
    if sum+n>=6:
        return sum
    else: 
        return 6-n
        
    # Return the minimum number of characters to make the password strong

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