local function q(i)
	print(i)
	io.flush()
	local s=io.read()
	if s=="Vacant" then
		return
	else
		return s
	end
end

local n=io.read("n")
local l=0
local r=n-1
local sl=q(l)
local sr=q(r)
while true do
	local m=(l+r)//2
	local sm=q(m)
	if l%2==m%2 and sl~=sm then
		r=m
		sr=sm
	elseif l%2~=m%2 and sl==sm then
		l=m
		sl=sm
	end
end