Platform

l = 15
w = 15
e = l/2
f = 0
i = 0

function MaterialsNeeded()
  print(l*w)
end

function Seti()
  print("From")
  if l%2 == 1 then
    i = .5
    print(i)
  else
   i = 0
  print(i)
end

function Setf()
  if w%2 == 1 then
    f = .5
    print("f" + f)
  else
    f = 0
    print("f" + f)
end


function Start()
  turtle.forward()
  DetectMaterial()
  turtle.placeDown()
  turtle.turnRight()
  print("To")
  print(e)
  print(" ")
  print(" ")
  repeat
    turtle.forward()
    DetectMaterial()
    turtle.placeDown()
    sleep(1)
    i = i + 1
    sleep(1)
    print(i)
  until i == e
  i = 0
end

function ComeBack()
  turtle.turnLeft()
  turtle.forward()
  turtle.turnLeft()
  DetectMaterial()
  turtle.placeDown()
  repeat
    turtle.forward
    DetectMaterial()
    turtle.placeDown()
    i = i + 1
    until i == l
  i = 0
end

function GoBack()
  turtle.turnRight()
  turtle.forward()
  DetectMaterial()
  turtle.placeDown()
  turtle.turnRight()
  repeat
    turtle.forward()
    DetectMaterial()
    turtle.placeDown()
    i = i + 1
  until i == l
  i = 0
end

function DetectMaterial()
  if turtle.getItemCount(1) >= 0 then
    turtle.select(1)
    sleep(1)
  elseif turtle.getItemCount(2) >= 0 then
    turtle.select(2)
    sleep(1)
  elseif turtle.getItemCount(3) >= 0 then
    turtle.select(3)
    sleep(1)
  elseif turtle.getItemCount(4) >= 0 then
    turtle.select(4)
    sleep(1)
  elseif turtle.getItemCount(5) >= 0 then
    turtle.select(5)
    sleep(1)
  elseif turtle.getItemCount(6) >= 0 then
    turtle.select(6)
    sleep(1)
  elseif turtle.getItemCount(7) >= 0 then
    turtle.select(7)
    sleep(1)
  elseif turtle.getItemCount(8) >= 0 then
    turtle.select(8)
    sleep(1)
  elseif turtle.getItemCount(9) >= 0 then
    turtle.select(9)
    sleep(1)
  elseif turtle.getItemCount(10) >= 0 then
    turtle.select(10)
    sleep(1)
  elseif turtle.getItemCount(11) >= 0 then
    turtle.select(11)
    sleep(1)
  elseif turtle.getItemCount(12) >= 0 then
    turtle.select(12)
    sleep(1)
  elseif turtle.getItemCount(13) >= 0 then
    turtle.select(13)
    sleep(1)
  elseif turtle.getItemCount(14) >= 0 then
    turtle.select(14)
    sleep(1)
  elseif turtle.getItemCount(15) >= 0 then
    turtle.select(15)
    sleep(1)
  else turtle.getItemCount(16) >= 0 then
    turtle.select(16)
    sleep(1)
end

function Platform()
  Seti()
  Setf()
  MaterialsNeeded()
  Start()
  repeat
    ComeBack()
    GoBack()
    f = f + 1
  until f == w/2
end