local t = {}
local offset = 200001
for i = 1, 800004 do
  t[i] = 0
end
local n = io.read("*n")
for i = 1, n do
  local x, r = io.read("*n", "*n")
  x = x + offset
  t[(x - r) * 2 + 1] = t[(x - r) * 2 + 1] + 1
  t[(x + r) * 2] = t[(x + r) * 2] - 1
end
local ret = 0
for i = 2, 800004 do
  t[i] = t[i] + t[i - 1]
  if ret < t[i] then ret = t[i] end
end
print(ret)