MOD = 998244353i64

read_line.to_i.times do
  puts solve()
end

def solve
  n = read_line.to_i
  xys = Array.new(n) { Tuple(Int64, Int64).from(read_line.split.map(&.to_i64)) }
  len = xys.map { |x, y| x ** 2 + y ** 2 }
  sum_len = len.sum % MOD
  ans = n.times.sum { |i| inv(len[i]) } % MOD
  ans *= sum_len
  ans %= MOD
  sum_re = 0i64
  sum_im = 0i64
  n.times do |i|
    div = inv(len[i])
    sum_re += (xys[i][0] ** 2 - xys[i][1] ** 2) * div
    sum_re %= MOD
    sum_im += xys[i][0] * xys[i][1] * 2 % MOD * div
    sum_im %= MOD
  end
  ans -= sum_re ** 2 + sum_im ** 2
  ans %= MOD
  ans += MOD if ans < 0
  return ans
end

def inv(v : Int64)
  pow(v, MOD - 2)
end

def pow(v : Int64, p)
  ret = 1i64
  while p > 0
    if (p & 1i64) != 0
      ret *= v
      ret %= MOD
    end
    v *= v
    v %= MOD
    p >>= 1
  end
  ret
end