!752

static int sep = 0;

p {
  load("sep");
}

static S lua = [[
  -- build a word tree (character occurrence tree) and walk it
  pairs = {}
  wordTree = {}
  wordTreeP = wordTree
  isSep = {}
  seps = "SEPS"
  for i = 1, seps:len() do isSep[seps:sub(i, i)] = true end
  function p(m, s)
    if s ~= nil then
      for i = 1, s:len() do
        local c = s:sub(i, i)
        if isSep[c] then
          wordTreeP = wordTree
        else
          local n = wordTreeP[c]
          if n == nil then n = {} wordTreeP[c] = n end
          wordTreeP = n
        end
      end
    end
    local c, n = next(wordTreeP)
    return c
  end
]];

static S strategy(S text) {
  if (sep >= 0x100) ret "done";
  sep++;
  save("sep");
  S seps = str((char) sep);
  print("Trying sep " + quote(seps));
  ret lua.replace([["SEPS"]], luaQuote(seps));
}

static void reset() {
  sep = 0;
  save("sep");
}