A block of mass \(M\) is released from rest from a vertical height \(h\) on a frictionless curved track and slides onto a frictionless horizontal surface. At the bottom of the track, the block collides with an identical block of mass \(M\) that is initially at rest and connected to an ideal horizontal spring of spring constant \(k\). In Trial 1, the two blocks stick together upon collision. In Trial 2, the collision between the two blocks is perfectly elastic, and the incoming block comes to rest immediately after the collision. What is the ratio of the maximum elastic potential energy stored in the spring in Trial 1 to that in Trial 2, \(\dfrac{U_{1,\text{max}}}{U_{2,\text{max}}}\)?