At his death, on January 1, 2017, Morris owned shares of ABC Corporation common stock, with a fair market value of $50 per share, which he had purchased in 2001 for $25 per share. If Morris's executor elected to value the estate by using the alternate valuation date, but then sold the shares through a broker-dealer on May 15, 2017, at $40 per share, what is the estate's basis per share for estate tax purposes