#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int T;
int N;
ll X[202020],Y[202020],R[202020],RR[202020];
const ll mo=998244353;
ll modpow(ll a, ll n = mo-2) {
	ll r=1;a%=mo;
	while(n) r=r*((n%2)?a:1)%mo,a=a*a%mo,n>>=1;
	return r;
}


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>T;
	while(T--) {
		cin>>N;
		
		ll RS=0;
		ll RRS=0;
		ll BIS=0,BRS=0,RBIS=0,RBRS=0;
		FOR(i,N) {
			cin>>X[i]>>Y[i];
			R[i]=X[i]*X[i]+Y[i]*Y[i];
			RR[i]=modpow(R[i]);
			(RS+=R[i])%=mo;
			(RRS+=RR[i])%=mo;
			
			(BIS+=(mo+X[i]*X[i]-Y[i]*Y[i])*RR[i])%=mo;
			(BRS+=(mo+2*X[i]*Y[i])*RR[i])%=mo;
			(RBIS+=(mo+X[i]*X[i]-Y[i]*Y[i])*RR[i])%=mo;
			(RBRS+=(mo-2*X[i]*Y[i])*RR[i])%=mo;
		}
		
		ll ret=RS*RRS%mo-(BIS*RBIS-BRS*RBRS);
		
		
		
		cout<<(ret%mo+mo)%mo<<endl;
	}
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}