Mining Wells

local rs = redstone
local name = shell.getRunningProgram()
function readArgs()
  local file = fs.open(name..".cfg", "r")
  distance = file.readLine()
  file.close()
end
function saveArgs()
  local file = fs.open(name..".cfg", "w")
  file.writeLine(distance)
  file.close()
end
readArgs()
if not distance == 0 then
 distance = distance - 1
 saveArgs()
 rs.setOutput("back", true)
end