AME: Notification should go to n number at a time.

Hello,        let me exaplain my doubt clearly.

Example:-If in the Payables invoice approval we have 3 persons

                  1.A

                   2.B

                   3.C

               Now i want to send the notifications to "A"and "B" at a time and the person who approves first will be considered and the notificaiton will be send to "C". 

Normally we select the serial and statics options for normal process.

So please let me know how can achieve this.

Thanks and Regards

VAMSI