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

local checker=function(l,sl,m,sm)
    if l%2==m%2 then
		return sl~=sm
	else
		return sl==sm
	end
end

local n=io.read("n")
print(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 checker(l,sl,m,sm) then
		r=m
		sr=sm
	else
		l=m
		sl=sm
	end
end