for i in range(int(input())) : if i==0 : xMin, yMin = map(int, input().split()) xMax, yMax = xMin, yMin continue x, y = map(int, input().split()) xMin, yMin, xMax, yMax = min(x,xMin), min(y,yMin), max(x,xMax), max(y,yMax) print((xMax-xMin)*(yMax-yMin))