Given the task definition and input, reply with output. In this task, you are given a list of integers and an integer k. You need to find the kth smallest element in the input list and return that.

[31, 78, 202, 71, 131, 121, 106, 123, 133, 221, 282, 141, 150, 255, 273, 237, 86, 38, 117, 171], k=18

255