Natyashastra
आदौ गुरुद्वयं कार्यं चतुर्दश लघून्यथ । उपोहनं विशालायाः पुनरन्ते गुरुः स्मृतः ॥ १२८॥
At the beginning of the Upohana of Viśālā, two long syllables are to be performed, followed by fourteen short syllables. The long syllable at the end is also prescribed.
english translation
Adau gurudvayaM kAryaM caturdaza laghUnyatha । upohanaM vizAlAyAH punarante guruH smRtaH ॥ 128॥
hk transliteration by Sanscript