URL：https://media.istockphoto.com/vectors/twenty-years-anniversary-celebration-logotype-collection-20th-logo-vector-id616853634?k=6&m=616853634&s=612x612&w=0&h=CYkaqVrI92voxLmIFbxsHeMpSAvpYfIjDfAHLOqc918=
掲載元：https://www.istockphoto.com/jp/イラスト/数字の20
