ヘ
https://pbs.twimg.com/media/GNn3aHTaIAAYalP.jpg#GNn3aHTaIAAYalP
https://www.psy.ritsumei.ac.jp/akitaoka/kinkaku5.jpg
https://upload.wikimedia.org/wikipedia/commons/6/60/Grey_square_optical_illusion.PNG
https://ja.wikipedia.org/wiki/%E9%8C%AF%E8%A6%96#/media/%E3%83%95%E3%82%A1%E3%82%A4%E3%83%AB:Grey_square_optical_illusion.PNG