#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    numbers = "0123456789"
    numbers = list(numbers)
    lower_case = "abcdefghijklmnopqrstuvwxyz"
    lower_case = list(lower_case)
    upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    upper_case = list(upper_case)
    special_characters = "!@#$%^&*()-+"
    special_characters = list(special_characters)
    count = 0
    flag1 = False
    flag2 = False
    flag3 = False
    flag4 = False
    flag5 = False
    for i in range(n):
        if password[i] in numbers:
            flag2 = True
        if password[i] in lower_case:
            flag3 = True
        if password[i] in upper_case:
            flag4 = True
        if password[i] in special_characters:
            flag5 = True
    if not flag2:
        count += 1
        n += 1
    if not flag3:
        count += 1
        n += 1
    if not flag4:
        count += 1
        n += 1
    if not flag5:
        count += 1
        n += 1
    if n > 6:
        flag1 = True
    else:
        count += 6-n
    return(count)
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)