#!/usr/bin/python

import os
import json
import subprocess

with open(os.devnull, 'w') as devnull:
    try:
        status = json.loads(subprocess.check_output(
            ['/usr/bin/env', 'juju', 'status', '--format=json'],
            stderr=devnull))
    except subprocess.CalledProcessError:
        print "-"
    else:
        print len(status["machines"]) - 1