local ins = {...}

local fnil = {}

for i = 1, #ins do
  local a = string.lower(ins[i])
  local b = tonumber(a)
  if b then
    if i == 1 or type(tonumber(ins[i - 1])) == "number" then
      error("Number in wrong pos", 0)
    end
    ins[i] = tostring(ins[i - 1]) .. a
    ins[i - 1] = fnil
  else
    if a == "down" or a == "up" or a == "left" or a == "right" or a == "forward"
      or a == "back" or a == "dig" or a == "digdown" or a == "digup"
        or a == "suck" or a == "suckdown" or a == "suckup" or a == "drop"
          or a == "dropdown" or a == "dropup" or a == "sel" then
    --

    else
      error(tostring(a) .. " is an invalid command.")
    end
    ins[i] = a
  end
end

for i = #ins, 1, -1 do
  local a = ins[i]
  if a == fnil then
    table.remove(ins, i)
  end
end

for i = 1, #ins do
  local a = ins[i]
  local cmd = a:match("%a+")
  local cnt = tonumber(a:match("%d+"))
  local cnt2
  if cmd == "sel" then
    cnt2 = 1
  else
    cnt2 = type(cnt) == "number" and cnt or 1
  end

  for o = 1, cnt2 do
    if cmd == "forward" then
      turtle.forward()
    elseif cmd == "back" then
      turtle.back()
    elseif cmd == "left" then
      turtle.turnLeft()
    elseif cmd == "right" then
      turtle.turnRight()
    elseif cmd == "down" then
      turtle.down()
    elseif cmd == "up" then
      turtle.up()
    elseif cmd == "dig" then
      turtle.dig()
    elseif cmd == "digdown" then
      turtle.digDown()
    elseif cmd == "digup" then
      turtle.digUp()
    elseif cmd == "drop" then
      turtle.drop()
    elseif cmd == "dropdown" then
      turtle.dropDown()
    elseif cmd == "dropup" then
      turtle.dropUp()
    elseif cmd == "suck" then
      turtle.suck()
    elseif cmd == "suckdown" then
      turtle.suckDown()
    elseif cmd == "suckup" then
      turtle.suckUp()
    elseif cmd == "sel" then
      turtle.select(cnt)
    else
      error("Invalid command caught late: " .. tostring(cmd))
    end
  end
end