Computation ofBillings Computation of Billings (in $K) Twelve MonthsEnded Three MonthsEnded Six MonthsEnded January31, July 31, July 31, 2017 2018 2017 2018 2017 2018 Revenue 381,459 518,504 125,543 167,044 239,041 322,852 Add: Contract Liabilities and Refund Liability, End of Period 195,501 282,943 214,405 300,426 214,405 300,426 Less: Contract Liabilities and Refund Liability, Beginning of Period (137,031) (195,501) (208,882) (293,667) (195,501) (282,943) Add: Contract Assets and Unbilled Accounts Receivable, Beginning of Period 2,532 10,095 10,400 14,555 10,095 16,899 Less: Contract Assets and Unbilled Accounts Receivable, End of Period (10,095) (16,899) (11,381) (16,196) (11,381) (16,196) Billings 432,366 599,142 130,085 172,162 256,659 341,038 37