local function query(x)
  io.write(x - 1 .. "\n")
  io.flush()
  local ret = io.read("*l")
  if ret == "Vacant" then os.exit() end
  return ret
end

local n = io.read("*n", "*l")
local first = query(1)
-- check-only
query(n)
local min, max = 1, n
while true do
  local mid = (min + max) // 2
  local ret = query(mid)
  local valid = false
  if mid % 2 == 0 and ret ~= first then
    valid = true
  end
  if mid % 2 == 1 and ret == first then
    valid = true
  end
  if valid then
    min = mid
  else
    max = mid
  end
end
