The `thread 1`{{execute interrupt}} command prints the stack of thread ID 1 - [thread command Docs](https://arthas.aliyun.com/en/doc/thread.html).

Arthas supports pipes, and you can find `main class`{{}} with `thread 1 | grep 'main('`{{execute T2}}.

You can see that `main class`{{}} is `demo.MathGame`{{}} :

```
$ thread 1 | grep 'main('
    at demo.MathGame.main(MathGame.java:17)
```