how to continue SID from last SID in target table duing increamental load..?

Hi Experts,

Am working on increamental load in SSIS and need your help in doing this process.

I Have done initial load and populated data into target table with new auto generated key SID.

I have 30 records in target now. few columns data got updated and i want to insert them in target table with new SID starting from 31. how can i achieve this in SSIS using CHANGE TRACKING.

NOTE : CANNOT USE SCD TYPES 

please guide me in this as am new to this tool.

Thankyou and Regards,

VJ.

vj_Vanamala.