N = gets.to_i
arr = Array.new(500_010, 0)

N.times do
  x, r = gets.split.map(&:to_i)
  x += 250_000

  arr[x - r] += 1
  arr[x + r] -= 1
end

ans = 0

1.upto(500_000) do |i|
  arr[i] += arr[i - 1]
  ans = arr[i] if ans < arr[i]
end

puts ans