Dime a Dozen Diamonds makes synthetic diamonds by treating carbon. Each diamond can be sold for $$170.$ The materials cost for a synthetic diamond is $$110.$ The fixed costs incurred each year for factory upkeep and administrative expenses are $$1,250,000.$ The machinery costs $$1\mathrm{.}21$ million and is depreciated straight$-$line over $10$ years to a salvage value of zero.

a$.$ What is the accounting break$-$even level of sales in terms of number of diamonds sold?

b$.$ What is the NPV break$-$even level of sales assuming a tax rate of $35\%,$ a $10-$year project life, and a discount rate of $12\%?($Do not round intermediate calculations. Round your final answer to the nearest whole number.$)$