Vijay,
One option could be to create a window of type 'FINAL' in FORM1. A final window is executed at the end of processing of your form. Here you have a count of total number of pages in FORM1, try exporting that to memory, you can use variable SFSY-FORMPAGES.
Similary, in FORM2 define a another window of type final. Have logic to import from memory total pages of FORM1, and then add SFSY-FORMPAGES( which is tot pages of FORM2). Add both of them to get the final count.
Hope this helps,
Thanks,
-VM.