What are both Challah and Kulich?
Kulich: Kulich (Russian: кули́ч ; ] , from Greek κόλλιξ - "kollix", and ultimately Hebrew: חלה‎ ‎ meaning a roll or loaf of bread) is a kind of Easter bread that is traditional in the Orthodox Christian faith and is eaten in countries like Russia, Belarus, Ukraine, Bulgaria, Romania, Georgia, Macedonia, Moldova and Serbia.
i don't know