#!/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 = "[!@#$%/^&/*/(/)-/+]"
    l1=len(re.findall(numbers, password))
    l2=len(re.findall(lower_case, password))
    l3=len(re.findall(upper_case, password))
    l4=len(re.findall(special_characters, password))
    c=0
    if(l1==0):
        c+=1
    if(l2==0):
        c+=1
    if(l3==0):
        c+=1
    if(l4==0):
        c+=1
    
    if((n+c)<6):
        c+= 6-(n+c)
    return c
'''
    print(password)
    print(l1)
    print(l2)
    print(l3)
    print(l4)
'''    

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