{"x1":-2,"x2":0}
{"x1":-1,"x2":1.28}
{"x1":-1,"x2":-1.28}
{"x1":0,"x2":0}
{"x1":1.4,"x2":-0.9}
{"x1":1.4,"x2":0}
{"x1":1.4,"x2":0.9}
{"x1":0.5,"x2":3}