#!/bin/python

import sys

def minimumNumber(n, password):
    lower, upper, special, digit = True, True, True,True
    for x in password:
        if x in '!@#$%^&*()-+':
            special = False
        elif x.islower():
            lower = False
        elif x.isupper():
            upper = False
        elif x.isdigit():
            digit = False
     
    if n < 6:
        return max(lower + upper + special + digit, 6-n)
    
    return lower + upper + special + digit

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