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

constexpr const int maxa=1000000001;
constexpr const ll mod=998244353;
ll euclid(ll a,ll b,ll& x,ll& y){
    if(b==0){
        x=1;y=0;
        return a;
    }else{
        ll d=euclid(b,a%b,x,y);
        ll t=x;
        x=y;
        y=t-(a/b)*y;
        return d;
    }
}
ll inv(ll p){
    ll x,y;
    euclid(p,mod,x,y);
    return (x+mod)%mod;
}
struct c{
    ll x,y;
    c(){x=0;y=0;}
    c(ll x,ll y):x(x),y(y){}
    ll abs(){
        return (x*x+y*y)%mod;
    }
    c conj(){
        return c(x,(mod-y)%mod);
    }
    void print(){
        cout<<to_string(x)+"+("+to_string(y)+")*i"<<endl;
    }
};
c operator+ (c x,c y){
    return c((x.x+y.x+2*mod)%mod,(x.y+y.y+2*mod)%mod);
}
c operator* (c x,c y){
    return c(((x.x+mod)%mod*(y.x+mod)%mod-(x.y+mod)%mod*(y.y+mod)%mod+mod)%mod,((x.x+mod)%mod*(y.y+mod)%mod+(x.y+mod)%mod*(y.x+mod)%mod+mod)%mod);
}
c operator/ (c x,ll y){
    return c(((x.x+mod)*inv(y))%mod,((x.y+mod)*inv(y))%mod);
}
c operator% (c x,ll y){
    return c((x.x+mod)%y,(x.y+mod)%y);
}
int main()
{
    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        vector<c> z(n);
        for(int i=0;i<n;i++){
            ll x,y;
            cin>>x>>y;
            z[i]=c(x,y);
        }
        vector<ll> sumsr(2);
        vector<c> sumsc(2);
        ll ans=0;
        for(int i=0;i<n;i++){
            ans+=sumsr[0]*inv(z[i].abs())+sumsr[1]*z[i].abs()-(sumsc[0]*(z[i].conj()*z[i].conj()/z[i].abs())+sumsc[1]*(z[i]*z[i]/z[i].abs())).x;
            //z[i].conj().print();
            //(z[i].conj()*z[i].conj()).print();
            //(z[i].conj()*z[i].conj()/z[i].abs()).print();
            //(sumsc[0]*(z[i].conj()*z[i].conj()/z[i].abs())+sumsc[1]*(z[i]*z[i]/z[i].abs())).print();
            sumsr[0]=(sumsr[0]+z[i].abs()+mod)%mod;
            sumsr[1]=(sumsr[1]+inv(z[i].abs())+mod)%mod;
            sumsc[0]=(sumsc[0]+z[i]*z[i]/z[i].abs())%mod;
            sumsc[1]=(sumsc[1]+z[i].conj()*z[i].conj()/z[i].abs())%mod;
            ans=(ans+mod)%mod;
        }
        cout<<ans<<endl;

    }
    return 0;

}