local x1, y1, z1 = gps.locate(5)
turtle.forward()
local x2, y2, z2 = gps.locate(5)

if x1 > x2 then
   turtle.turnRight()
elseif x1 == x2 then
   if z1 > z2 then
      --we're ok
   else
      turtle.turnRight()
      turtle.turnRight()
   end
else
   turtle.turnRight()
   turtle.turnRight()
   turtle.turnRight()
end