eq00trueeq0sxfalseeqsx0falseeqsxsyeqxyortrueytrueorfalseyyunionemptyhhunionedgexyihedgexyunionihisEmptyemptytrueisEmptyedgexyifalsefromedgexyixtoedgexyiyrestedgexyiirestemptyemptyreachxyihif1eqxyisEmptyieqxfromieqytoixyihif1trueb1b2b3xyihtrueif1falseb1b2b3xyihif2b1b2b3xyihif2trueb2b3xyihfalseif2falseb2b3xyihif3b2b3xyihif3falseb3xyihreachxyrestiedgefromitoihif3trueb3xyihif4b3xyihif4truexyihtrueif4falsexyihorreachxyrestihreachtoiyunionrestihemptyeqsxsyeqxyunionedgexyihunionihreachxyihtoireachxyiheqytoireachxyihfromireachxyiheqxfromireachxyihisEmptyireachxyiheqxyreachxyihif1eqxyisEmptyieqxfromieqytoixyihif1falseb1b2b3xyihif2b1b2b3xyihif2falseb2b3xyihif3b2b3xyihif3falseb3xyihtoiif3falseb3xyihfromiif3falseb3xyihrestiif3falseb3xyihreachxyrestiedgefromitoihif3trueb3xyihif4b3xyihif4falsexyihunionrestihif4falsexyihtoiif4falsexyihreachtoiyunionrestihemptyif4falsexyihrestiif4falsexyihreachxyrestihif4falsexyihorreachxyrestihreachtoiyunionrestihemptytrueif4falsexyihreachtoiyunionrestihemptyreachxyihif1eqxyisEmptyieqxfromieqytoixyihif1falseb1b2b3xyihif2b1b2b3xyihif2falseb2b3xyihif3b2b3xyihif3falseb3xyihreachxyrestiedgefromitoihif3trueb3xyihif4b3xyihif4falsexyihreachxyrestihtrueif4falsexyihorreachxyrestihreachtoiyunionrestihemptyfalseif4falsexyihrestifalseif4falsexyihtoifalseif4falsexyihunionrestihfalseunionedgexyihunionihtrue1union241022if4501022304050if360102032405060if27010203042506070if1801020304052607080reach4012203040rest1210to1110from1114isEmpty1010edge31142135union211121empty00or201120false00s1010true00eq201020000if3falseb3xyihrestifalseif3falseb3xyihfromifalseif3falseb3xyihtoifalsereachxyiheqxyfalsereachxyihisEmptyifalsereachxyiheqxfromifalsereachxyihfromifalsereachxyiheqytoifalseeqsxsyeqxytrue1eq281426if4501020304050if360102030405060if27010203040506070if1801020304050607080reach4010203040rest1812to1414from1210isEmpty1010edge38182134union241420empty01or201420false00s1411true00eq2811020000reachxyihtoifalse