#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    lower_case = list("abcdefghijklmnopqrstuvwxyz")
    upper_case = list("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
    special_characters = list("!@#$%^&*()-+")
    numbers = list("0123456789")
    c=0
    d=0
    if n<6:
        c=6-n
    f=0
    for i in password:
        if i in lower_case:
            f=1
            break
    if f!=1:
        d+=1
    else:
        f=0
    for i in password:
        if i in upper_case:
            f=1
            break
    if f!=1:
        d+=1
    else:
        f=0
    for i in password:
        if i in special_characters:
            f=1
            break
    if f!=1:
        d+=1
    else:
        f=0
    for i in password:
        if i in numbers:
            f=1
            break
    if f!=1:
        d+=1
    else:
        f=0
    return max(d,c)

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