#!/bin/python3

import sys

def minimumNumber(n, s):
    numbers = "0123456789"
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    special_characters = "!@#$%^&*()-+"
    counter=0
    small=0
    cap=0
    num=0
    sp=0
    for i in range(n):
        if s[i] in lower_case:
            small=1
        elif s[i] in upper_case:
            cap=1
        elif s[i] in numbers:
            num=1
        elif s[i] in special_characters:
            sp=1

    if small==0:
        counter+=1
        n+=1
    if cap==0:
        counter+=1
        n+=1
    if num==0:
        n+=1
        counter+=1
    if sp==0:
        n+=1
        counter+=1
    if n<6:
        counter=counter+(6-n)
        
    return counter
            
            
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)