#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
	// (z_i * z_i - z_j * z_j) / z_i * z_j
	// (z_i ^ 4 + z_j ^4 - 2 * z_i^2 * z_j^2) / z_i^2 * z_j^2
	// z_i^2 / z_j^2 + z_j^2 / z_i^2 - 2
	int t;
	cin >> t;
	while(t--){
		int n;
		cin >> n;
		vector<mint> z(n);
		vector<mint> c(n), d(n);
		rep(i,n){
			int x, y;
			cin >> x >> y;
			z[i] = x*x+y*y;
			c[i] = x*x-y*y;
			d[i] = x*y;
		}
		mint ans = 0;
		mint sumz = 0;
		mint invsumz = 0;
		mint sumc = 0;
		mint sumd = 0;
		rep(i,n) sumz += z[i];
		rep(i,n) invsumz += 1/z[i];
		rep(i,n) sumc += c[i]/z[i];
		rep(i,n) sumd += d[i]/z[i];
		dbg(sumz.val());
		rep(i,n-1){
			sumz -= z[i];
			invsumz -= 1/z[i];
			sumc -= c[i]/z[i];
			sumd -= d[i]/z[i];
			ans += sumz/z[i] + z[i]*invsumz - 2*c[i]/z[i]*sumc-8*d[i]/z[i]*sumd;
		}
		cout << ans.val() << endl;
	}
	return 0;
}