def solve():
    def complex_inverse(z):
        x, y = z
        h = (x * x + y * y) % Mod
        h_inv = pow(h, -1, Mod)
        return (x * h_inv % Mod, - y * h_inv % Mod)

    def complex_conj(z):
        return (z[0], -z[1])

    def complex_add(z1, z2):
        (x1, y1) = z1; (x2, y2) = z2
        return ((x1 + x2) % Mod, (y1 + y2) % Mod)

    def complex_mul(z1, z2):
        (x1, y1) = z1; (x2, y2) = z2
        return ((x1 * x2 - y1 * y2) % Mod, (x1 * y2 + x2 * y1) % Mod)


    Mod = 998244353

    N = int(input())
    z = [None] * N; z_inv =[None] * N
    for i in range(N):
        x, y = map(int, input().split())
        z[i] = (x, y)
        z_inv[i] = complex_inverse(z[i])

    p = sum((x * x + y * y) % Mod for x,y in z) % Mod
    q = sum((x * x + y * y) % Mod for x,y in z_inv) % Mod

    beta_sum = (0, 0)
    beta_inv_sum = (0, 0)

    for i in range(N):
        beta = complex_mul(z[i], complex_conj(z_inv[i]))
        beta_sum = complex_add(beta_sum, beta)
        beta_inv_sum = complex_add(beta_inv_sum, complex_inverse(beta))

    return (p * q - complex_mul(beta_sum, beta_inv_sum)[0]) % Mod

#==================================================
import sys
input=sys.stdin.readline
write=sys.stdout.write

T = int(input())
write("\n".join(map(str, [solve() for _ in range(T)])))