N = gets.to_i

v_counter = Hash.new(0)
h_counter = Hash.new(0)

N.times do
  a, b, t = gets.split.map(&:to_i)

  if a == 0
    v_counter[b + t] += 1
  else
    h_counter[b + t] += 1
  end
end

ans = 0

v_counter.each do |t, cnt|
  ans += h_counter[t] * cnt
end

puts ans