#!/bin/python

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
    if n >= 6:
        lenok=True
    else:
        lenok=False
        adding=6-n
    if set('1234567890').intersection(password):
        numok=True
    else:
        numok=False
    if set('ABCDEFGHIJKLMNOPQRSTUVWXYZ').intersection(password):
        upok=True
    else:
        upok=False
    if set('abcdefghijklmnopqrstuvwxyz').intersection(password):
        downok=True
    else:
        downok=False
    if set('!@#$%^&*()-+').intersection(password):
        spok=True
    else:
        spok=False
        
    output=0
    if lenok==True:
        if numok==False:
            output+=1
        if upok==False:
            output+=1
        if downok==False:
            output+=1
        if spok==False:
            output+=1
    else:
        output=adding
        if numok==False:
            output-=1
        if upok==False:
            output-=1
        if downok==False:
            output-=1
        if spok==False:
            output-=1
        if output >= 0 :
            return adding
        else:
            output=-output
            return output+adding
    return output
if __name__ == "__main__":
    n = int(raw_input().strip())
    password = raw_input().strip()
    answer = minimumNumber(n, password)
    print answer