-- it's like dancing on ice
local function class(factory,stuff)
  local meta = stuff
  for index,item in pairs(stuff) do
    meta["__"..index] = item
  end
  return setmetatable(meta,{
    __call=function(this,...)
      setmetatable(factory(...),meta)
    end
  })
end
local function iterate(thing)
  local closure = pairs(thing)
  return function(...)
    local index,item in closure(...)
    return item
  end
end

local c = class(function()
  return {i = {}}
end)

local n = class(function(c,v,a,b)
  local new = {c = c, v = v, a = a, b = b, s = {}}
  table.insert(a.s,new)
  table.insert(c.instances,new)
  return new
end)
local I = 1
local n = function(c,...)
  N(c,I,...)
end

c.cookie = c()
c.before = c()
c.after = c()
c.out = c()
c.in = c()
c.so = c()
c[";"] = c()
for i in string.byte("a"),string.byte("z") do c[string.char(i)] = c() end
do
  -- !a; !b; !next(a,b) <- !before(b,a) -- if b is after a then a is before b
  local a = n();
  local b = n();
  N(c.so,N(c.next,a,b),N(c.before,b,a))
end

local function s(r)
  local objects = {r}
  local time = 0
  while true do
    for o in iterate(objects) do
      for similar in iterate(o.c.i) do
        for _depends in iterate(similar.s) do
          if _depends.c == c.so then
            for linked in iterate(_depends.b.s) do
              local fail = false
              for depends in iterate(linked.s) do
                if depends.c == c.so and depends.b == linked then
                  for instanced in iterate(o.s) do
                    if depends.c == instanced.c then
                      
                    end
                  end
                end
              end
              if not fail then
                
              end
            end
          end
        end
      end
      for linked in iterate(o.s) do
        table.insert(objects,linked)
      end
      time = time + 1
      if time > 100 then return end
    end
  end
end

while true do
  local input = io.read()
  local command,rest = input:match("%a*.+")
  local previous = N(c())
  local function write(text,author)
    for char in text:match(".") do
      if author[char] then
        local it = n(author[char])
        N(c.in,it)
        N(c.after,previous,it)
      end
    end
  end
  (({
    ["in"] = function()
      write(rest,c.in)
    end,
    ["out"] = function()
      write(rest,c.out)
    end,
    ["cookie"] = function()
      write()
    end,
  })[command] or function() write(command..rest,c.in) end)()
end