#include // #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; // using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> // using mint = modint998244353; template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } ll my_pow(ll x, ll n, ll mod) { //  繰り返し二乗法.x^nをmodで割った余り. ll ret; if (n == 0) { ret = 1; } else if (n % 2 == 1) { ret = (x * my_pow((x * x) % mod, n / 2, mod)) % mod; } else { ret = my_pow((x * x) % mod, n / 2, mod); } return ret; } ll inv(ll x, ll mod) { return my_pow(x, mod - 2, mod); } int main() { ll T; cin >> T; while (T--) { ll N; cin >> N; vector x(N); vector y(N); for (ll i = 0; i < N; i++) { cin >> x[i] >> y[i]; x[i] = (x[i] + mod2) % mod2; y[i] = (y[i] + mod2) % mod2; } ll val1 = 0; for (ll i = 0; i < N; i++) { val1 += (x[i] * x[i] + y[i] * y[i]) % mod2; val1 %= mod2; } ll val2 = 0; for (ll i = 0; i < N; i++) { val2 += inv((x[i] * x[i] + y[i] * y[i]) % mod2, mod2); val2 %= mod2; } ll val3_re = 0; ll val3_im = 0; ll val4_re = 0; ll val4_im = 0; for (ll i = 0; i < N; i++) { ll xxyy_inv = inv((x[i] * x[i] + y[i] * y[i]) % mod2, mod2); val3_re += ((x[i] * x[i] - (y[i] * y[i]) % mod2 + mod2) % mod2) * xxyy_inv; val3_re %= mod2; val3_im += ((2 * x[i] * y[i])) * xxyy_inv; val3_im %= mod2; val4_im += (mod2 - (((2 * x[i] * y[i])) * xxyy_inv) % mod2) % mod2; val4_im %= mod2; } val4_re = val3_re; ll ans = (val1 * val2) % mod2; ans = (ans + mod2 - (val3_re * val4_re + mod2 - (val3_im * val4_im) % mod2) % mod2) % mod2; cout << ans << endl; } }