Question: Dromton's teacher was the disciple of a man who was one of how many Buddhist Mahasiddhas?
Sentence (from "Atiśa"): Atīśa Dīpaṃkara Śrījñāna (Bengali: অতীশ দীপংকর শ্রীজ্ঞান ; Standard Tibetan: ཇོ་བོ་རྗེ་དཔལ་ལྡན་ཨ་ཏི་ཤ། ; ) (982 - 1054 CE) was a Buddhist Bengali religious leader and master.
Relevant evidence: No