#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

void solve(){
	int n; cin >> n;
	vector<ll> x(n), y(n);
	rep(i,0,n) cin >> x[i] >> y[i];

	vector<mint> norm(n);
	vector<mint> invnorm(n);
	rep(i,0,n){
		norm[i] = (mint(x[i] * x[i]) + mint(y[i] * y[i]));
		invnorm[i] = norm[i].inv();
	}

	mint ans = 0;

	// RED
	{
		mint sminv = sum(invnorm);
		rep(i,0,n){
			ans += (sminv - invnorm[i]) * mint(x[i] * y[i]) * mint(x[i] * y[i]) * invnorm[i] * 4;
		}
	}

	// BLUE
	{
		mint sminv = sum(invnorm);
		rep(i,0,n){
			mint k1 = mint(x[i]) * mint(x[i]) * mint(x[i]) * mint(x[i]);
			mint k2 = mint(y[i]) * mint(y[i]) * mint(y[i]) * mint(y[i]);
			ans += (sminv - invnorm[i]) * (k1 + k2) * invnorm[i] * 2;
		}
	}

	// GREEN
	{
		mint tmp = 0;
		rep(i,0,n){
			tmp += invnorm[i] * (mint(y[i]) * mint(y[i]) - mint(x[i]) * mint(x[i]));
		}
		rep(i,0,n){
			ans += (tmp - invnorm[i] * (mint(y[i]) * mint(y[i]) - mint(x[i]) * mint(x[i])))
					 * (mint(x[i]) * mint(x[i]) - mint(y[i]) * mint(y[i])) * invnorm[i] * 2;
		}
	}

	// YELLOW
	{
		vector<mint> tmp(n);
		rep(i,0,n){
			tmp[i] = invnorm[i] * mint(x[i]) * mint(y[i]);
		}
		mint tmpsum = sum(tmp);
		rep(i,0,n){
			ans -= tmp[i] * 8 * (tmpsum - tmp[i]);
		}
	}

	ans /= 2;
	

	cout << ans.val() << '\n';
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int t; cin >> t;
	while(t--) solve();
}