ll@(x,y)[3],L[4]{1,-1,0,0},U[4]{0,0,1,-1};wt(max[i,0,64](abs((x[2]+L[i>>4]-x[0]-L[i&3])*(y[1]+U[i>>2&3]-y[0]-U[i&3])-(x[1]+L[i>>2&3]-x[0]-L[i&3])*(y[2]+U[i>>4]-y[0]-U[i&3]))/2.0));