How to Auto Approve contracts when the Approver and the signer is same

We have a requirement to auto approve the contract, if the Approver is part of the Approval Hierarchy and the signer is also same then the contract has to be auto approved and sent for signature.

Ex: A contract is created with amount of 500 and 0-500 will be routed to User A in the hierarchy, the same user is selected for Signer in Parties Tab. In this case contract needs to be Auto Approved and It has to be sent for Signature with User A.