local mce, mfl, msq, mmi, mma, mab = math.ceil, math.floor, math.sqrt, math.min, math.max, math.abs
local bls, brs = bit.lshift, bit.rshift
local bor, band = bit.bor, bit.band
local BITBOX = {}

BITBOX.initialize = function(self, lim)
  self.lim = lim
  self.sz = 30
  self.way = true
  self.bcnt = mce(lim / self.sz)
  self.b1 = {}
  for i = 1, self.bcnt do
    self.b1[i] = 0
  end
  self.curmax = 0
end

BITBOX.set = function(self, x)
  local group = mce(x / self.sz)
  local idx = x - (group - 1) * self.sz
  self.b1[group] = bor(self.b1[group], bls(1, idx - 1))
end

BITBOX.query = function(self, x)
  local group = mce(x / self.sz)
  local idx = x - (group - 1) * self.sz
  return band(self.b1[group], bls(1, idx - 1)) ~= 0
end
BITBOX.new = function(n)
  local obj = {}
  setmetatable(obj, {__index = BITBOX})
  obj:initialize(n)
  return obj
end
local bbprime = BITBOX.new(50000000)
local bbsq = BITBOX.new(50000000)

local function comp(a, b)
  return a < b
end

local function lower_bound(ary, x)
  local num = #ary
  if num == 0 then return 1 end
  if not comp(ary[1], x) then return 1 end
  if comp(ary[num], x) then return num + 1 end
  local min, max = 1, num
  while 1 < max - min do
    local mid = mfl((min + max) / 2)
    if comp(ary[mid], x) then
      min = mid
    else
      max = mid
    end
  end
  return max
end

local function getprimes(x)
  local primes = {}
  local withsq = {1}
  for i = 2, x do
    if bbsq:query(i) then
      table.insert(withsq, i)
    end
    if not bbprime:query(i) then
      table.insert(primes, i)
      local lim = mfl(x / i)
      for j = 2, lim do
        bbprime:set(j * i)
      end
      if 4 < i then
        lim = mfl(x / (i * i))
        for j = 1, lim do
          if 0 < j % 4 and 0 < j % 9 then
            bbsq:set(j * i * i)
          end
        end
      end
    end
  end
  return primes, withsq
end

local n = io.read("*n")
local primes, withsq = getprimes(n)
-- print(table.concat(withsq, " "))
-- print(#primes, #withsq)
-- print(os.clock())
local t = {}
local baselim = 1
while (baselim + 1) * (baselim + 1) <= n do
  baselim = baselim + 1
end
local ans = baselim * baselim
for base = 1, baselim do
  local cnt = mfl(n / (base * base))
  local lb = lower_bound(withsq, cnt + 1)
  cnt = cnt - mfl(cnt / 4) - mfl(cnt / 9) + mfl(cnt / 36) - (lb - 1)
  ans = ans + cnt * (2 * base - 1)
end
print(ans)
-- print(os.clock())