import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes")
no = lambda :print("no");No = lambda :print("No")
#######################################################################
mod = 998244353
def mul(a, b):
    return ((a[0] * b[0] - a[1] * b[1]) % mod, (a[0] * b[1] + a[1] * b[0]) % mod)
def add(a, b):
    return ((a[0] + b[0]) % mod, (a[1] + b[1]) % mod)

def norm(a):
    return (a[0] * a[0] + a[1] * a[1]) % mod

def div(a, b):
    return mul(mul(a, (b[0], -b[1])) , (pow(norm(b), mod - 2, mod), 0))

for i in range(ni()):
    n = ni()
    p = [na() for _ in range(n)]
    normP = [norm(x) for x in p]
    B = 0
    for i in range(n):
        B = (B + normP[i]) % mod
    C = 0
    for i in range(n):
        C = (C + pow(normP[i], mod - 2, mod)) % mod
    D = (2 * B * C) % mod
    D -= n * 2
    D *= pow(2, mod - 2, mod)
    for i in range(n):
        p[i] = mul(p[i], p[i])
        p[i] = div(p[i], (normP[i], 0))
    sum = (0, 0)
    inv_p = [div((1, 0), x) for x in p]
    sumP = (0, 0)
    for i in range(n):
        sumP = add(sumP, p[i])
    sumP_inv = (0, 0)
    for i in range(n):
        sumP_inv = add(sumP_inv, inv_p[i])
    ans = mul(sumP, sumP_inv)
    ans = add(ans, (-n, 0))
    print((D-ans[0])%mod)