History Stack of activity clear in android -

i need clear history of activities. have 5 activities. in first 4 activities have make button go , fro data filled in screens. proceed on 5th screen need reset history , start intent new stack. after press in 5th screen app should exit. tried using launchmode , nohistory , flags such new_task , clear_top, clear_task still unable achieve this. please me. suggest me how achieve this.

in comments suggested you've tried using flags like:

intent = new intent(mainactivity.this,secondactivity.class);      i.addflags(android.flags.flag_clear_top | flag_new_task | flag_clear_task) 

but instead try using them like:

intent intent = new intent(mainactivity.this,secondactivity.class); intent.addflags(intent.flag_activity_clear_top|intent.flag_activity_new_task|intent.flag_activity_clear_task);