Alice Bob play game initially stre s_1 s_2 dot s_n consist character x they alternate turn Alice move during turn player select contiguous substring consist character replace X Alice select subste length Bob select substre length b it guarantee bFor example s x 3 b 2 Alices string turn xxxx and Bobs turn stre s X Bobs string turn XXX XXX XXXWhoever unable lose you determine win play optimallyyou answer q independent query