panic: invalid argument to Intn

goroutine 1 [running]:
math/rand.(*Rand).Intn(0x1ef320?, 0x1ef858?)
	/usr/local/go/src/math/rand/rand.go:180 +0x64
math/rand.Intn(0x0)
	/usr/local/go/src/math/rand/rand.go:464 +0x28
main.main()
	/home/ubuntu/codeforces/0-999/100-199/160-169/160/verifierE.go:43 +0x678
exit status 2