-- a, b are the last 2 words

pairs = {}

text = {}

ntext = 0

word = {}

wordIdx = {}

function p(m, s)

  if s ~= nil then

    for i = 1, s:len() do

      local c = s:sub(i, i)

      ntext = ntext+1

      text[ntext] = c

      if c >= "a" and c <= "z" or c >= "A" and c <= "Z" then

        nword = nword+1

        word[nword] = c

      else

        if nword ~= 0 then

          newWord(table.concat(word))

          word = {}

          nword = 0

        end

      end

    end

  end

  local x = wordIdx[b]

  if x ~= nil then return table.concat(text, "", x,

    math.min(ntext, x+math.min(100, m)-1)) end

end

function newWord(w)

  a = b

  b = w

  wordIdx[b] = ntext+1

end