local ffi = require("ffi")
local C = ffi.C
ffi.cdef[[
long long atoll(const char*);
]]

local function lltonumber(str)
  return C.atoll(str)
end
local d = io.read()
d = lltonumber(d)
local ans = d

local function solve(x, rep)
  local ret = x
  for i = 1, rep do
    x = x / 2LL
    ret = ret + x
  end
  return ret
end

for i = 1, 64 do
  local min = 0LL
  local max = d
  while 1LL < max - min do
    local mid = (min + max) / 2LL
    if d <= solve(mid, i) then
      max = mid
    else
      min = mid
    end
  end
  if d == solve(max, i) then
    ans = max
  end
end
ans = tostring(ans):gsub("LL", "")
print(ans)