#!/bin/python

import sys
import string
numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"
def minimumNumber(n, password):
    count =5
    length=len(password)
    j=0
    for i in password:
        if i in numbers:
            count-=1
            break
    if count !=4:
        j+=1
    count=5
    for i in password:
        if i in lower_case:
            count-=1
            break
    if count !=4:
        j+=1
    count=5
    for i in password:
        if i in upper_case:
            count-=1
            break
    if count !=4:
        j+=1
    count=5
    for i in password:
        if i in special_characters:
            count-=1
            break
    if count !=4:
        j+=1
    count=5
    ab=length+j
    if ab<6:
        return 6-ab+j
    else:
        return j
        
            
    # Return the minimum number of characters to make the password strong

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