Mahabharata 1.2.231

1.2.231

atrādhyāyāstrayaḥ proktāḥ ślokānāṃ ca śataṃ tathā |
viṃśatiśca tathā ślokāḥ saṃkhyātāstattvadarśinā || 231 ||

[paragraph continues] In this, they came across Agni, having arrived on the shore of the sea of red waters. In this, asked by Agni himself, Arjuna worshipped him duly, returned to him the excellent celestial bow called Gandiva. In this, leaving his brothers who dropped one after another and Draupadi also, Yudhishthira went on his journey without once looking back on them. This the seventeenth Parva is called Mahaprasthanika. The number of sections in this is three. The number of slokas also composed by Vyasa cognisant of truth is three hundred and twenty.