Get Sum (Total) from two sub reports in Crystal Report in ASP.Net

I want to sum two value, which is on two subreport in crystal report.

how it will get done.

I tried but it is not getting done

Main Report
Shared Numbervar GrandTotal := 0;
Global Numbervar GroupTotal := 0;

First Sub Report
 Global Numbervar GroupTotal;
 GroupTotal := Sum({@Total});
 
Second SubReport

WhilePrintingRecords;
Shared NumberVar Total2 := ({SP_Pending_Customer_Amt;1.I_Amt});