bon apetit. when you are done, i will donate one million dollars to charity of your choice. i don't have one million dollars. i will still honor my promise.
there is 2^64 - 1 (roughly 5.53 * 10^17 1,84 × 10^19) grains of rice on the board.
according to google, grain of rice averages at about 30 miligrams (per random google result), which makes the rice on the board to weigh about 553 402 322 211 metric tons.
The total world rice production for 2022 was 776 461 457 metric tonnes (per wiki).
((2^64−1) × 0.03) / (10^6) / 776461457 = 712,72
so there is about 712 times as much rice as the whole earth's 2022 rice production.
this is why it is important to understand basic math in school, even if you don't plan to become a scientist.
because then the covid comes, and all these university of life graduates with their youtube research and common sense have absolutely no idea how fast the exponential curve is growing and what it means for the spread of the illness.
i understand you might have known this and being sarcastic with your post.