Which work in India is called "the first poem"?

The main story of Ramayana is vivid and exciting. Compared with Mahabharata, it has been greatly improved in compiling style and literary description, so it is called "original poem", which also shows that ancient Indian literary creation has made great progress. Ramayana has a far-reaching influence on later Indian literature and world literature. His creative methods and materials are often used for reference by later works.