panic: invalid argument to Intn

goroutine 1 [running]:
math/rand.(*Rand).Intn(0x4000020210?, 0x5?)
	/usr/local/go/src/math/rand/rand.go:180 +0x64
main.generateTests()
	/home/ubuntu/codeforces/2000-2999/2100-2199/2150-2159/2156/verifierC.go:137 +0x264
main.main()
	/home/ubuntu/codeforces/2000-2999/2100-2199/2150-2159/2156/verifierC.go:38 +0x158
exit status 2