In which direction does the train with an ellipse-shape car run?
shape = 'ellipse'
SELECT T2.direction FROM cars AS T1 INNER JOIN trains AS T2 ON T1.train_id = T2.id WHERE T1.shape = 'ellipse'
database name:db_id trains
cars table cars Cols: id dtype integer, train id dtype integer, position dtype integer, shape dtype text, length dtype text, sides dtype text, roof dtype text, wheels dtype integer, load_shape dtype text, load number dtype integer, 
trains table trains Cols: id dtype integer, direction dtype text, 
