func GenerateRandomInt64(min, max int64) int64 {
	upper := max - min

	nBig, err := rand.Int(rand.Reader, big.NewInt(upper))

	if err != nil {
		panic(err)
	}

	return nBig.Int64() + min
}
func GenerateRandomInt64(min, max int64) int64 {
	upper := max - min

	nBig, err := rand.Int(rand.Reader, big.NewInt(upper))

	if err != nil {
		panic(err)
	}

	return nBig.Int64() + min
}
// Generate random number in [0,n)