n = io.read("*n")
v = {}
c = 0
t = {}
for i = 1, n do
  tp = io.read("*n")
  a, b = io.read("*n", "*n")
  a = a - b
  if tp == 1 then
    if not v[a] then v[a] = 1 else v[a] = v[a] + 1 end
  else
    table.insert(t, a)
  end
end
for i = 1, #t do
  a = t[i]
  if v[a] then c = c + v[a] end
end
print(c)