1. National Institute of Informatics, ERATO, Kawarabayashi Large Graph Project, 2-1-2 Hitotsubashi, Chiyoda-ku, 101-8430 Tokyo, Japan
2. JST, ERATO, Kawarabayashi Large Graph Project, 2-1-2 Hitotsubashi, Chiyoda-ku, 101-8430 Tokyo, Japan
3. Preferred Infrastructure, 1-6-1 Otemachi, Chiyoda-ku, 100-0004 Tokyo, Japan