panic: runtime error: negative shift amount

goroutine 1 [running]:
main.solve(0x4000096180, 0x40000ac040)
	/tmp/cf-worker-4143192169/1543E.go:34 +0x570
main.main()
	/tmp/cf-worker-4143192169/1543E.go:74 +0x1ec
exit status 2
failed to run official solver: exit status 1