#!/bin/python

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    l = 6
    digit = 1
    lower = 1
    upper = 1
    special = 1
    if n<6:
        c = 6-n
    else:
        c = 0
    
    for i in password:
        if i in '!@#$%^&*()-+':
            special = 0
        if 48<=ord(i) and ord(i)<=57:
            digit = 0
        if 65<=ord(i) and ord(i)<=90:
            upper = 0
        if 97<=ord(i) and ord(i)<=122:
            lower = 0
    more = special + upper + lower + digit
    if c == 0:
        return more
    elif c>=more:
        return c
    else:
        return more

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