#!/bin/python3

import re
import sys

RE_DIG = re.compile('\d')
RE_UPP = re.compile('[A-Z]')
RE_LOW = re.compile('[a-z]')
RE_SPE = re.compile('[-!@#$%^&*()+]')


def minimumNumber(n, password):
    addChars = 0
    # at least 1 digit
    if RE_DIG.search(password) is None:
        addChars = addChars +1
    # at least 1 lowercase
    if RE_UPP.search(password) is None:
        addChars = addChars +1
    # at least 1 uppercase
    if RE_LOW.search(password) is None:
        addChars = addChars +1
    # at least 1 special
    if RE_SPE.search(password) is None:
        addChars = addChars +1
    # len at least 6
    if n+addChars < 6:
        addChars = 6-n
    return addChars

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