The Company is required in periods in which it has net income to calculate basic earnings per share (“basic EPS”) using the two-class method. The two-class method is required because the Company’s shares of Series N preferred shares, each of which is convertible to 40 common shares, have the right to receive dividends or dividend equivalents should the Company declare dividends on its common stock. Under the two-class method, earnings for the period are allocated on a pro-rata basis to the common and preferred stockholders. The weighted-average number of common and preferred shares outstanding during the period is then used to calculate basic EPS for each class of shares.

In periods in which the Company has a net loss, basic loss per share is calculated by dividing the loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period. The two-class method is not used in periods in which the Company has a net loss because the preferred stock does not participate in losses.

Stock options and other potential common shares are included in the calculation of diluted earnings per share (“diluted EPS”), since they are assumed to be exercised or converted, except when their effect would be anti-dilutive. The table below shows the calculation of the shares used in computing diluted EPS.

	Three Months Ended March 31,
Weighted Average Shares Calculation:	2021		2020
Basic weighted average shares outstanding		34,788,016		28,751,689
Treasury stock effect of common stock options and restricted stock awards		2,745,049		1,448,425
Diluted weighted average common shares outstanding		37,533,065		30,200,114

For the three months ended March 31, 2021 and 2020, there were potential common shares of 30,000 and approximately 0.1 million, respectively, that were excluded from the computation of diluted EPS, as the inclusion of such common shares would have been anti-dilutive.