I,R=input,range
P=998244353
for t in R(int(I())):
	N=int(I())
	a=b=d=e=f=g=0
	for i in R(N):
		x,y=map(int,I().split())
		z=x*x+y*y
		w=pow(z,-1,P)
		a,b,d,e,f,g=a+b*z+i*2+(d-e*x*x-f*x*y-g*y*y)*w,b+w,d+z,e+4*x*x*w,f+8*x*y*w,g+4*y*y*w
	print(a%P)