Maxey Inc. enters into a contract with a customer to provide a perpetual software license, installation services, and three years of post-contract customer support (such as future upgrades and telephone support). The installation services require Maxey Inc. to substantially customize the software by adding significant new functionality enabling the software to function with other computer systems owned by the customer. The upgrades and telephone support do not significantly affect the softwares benefit or value to the customer. How many performance obligations are in the contract?