diff --git a/build.lua b/build.lua
index b55c670..f352f64 100644
--- a/build.lua
+++ b/build.lua
@@ -121,3 +121,5 @@ if mode == 'center' then
 else
     move_back_to_top_corner(grid)
 end
+
+file:close()
diff --git a/build_circle.lua b/build_circle.lua
new file mode 100644
index 0000000..bfceba1
--- /dev/null
+++ b/build_circle.lua
@@ -0,0 +1,95 @@
+local robot = require('robot')
+local nav = require('nav')
+local io = require('io')
+
+local filename = ...
+
+if not filename then
+    print('Usage: build_circle <filename>')
+    print('The robot starts in the center')
+    return 1
+end
+
+
+local file = io.open(filename, 'r')
+
+if not file then
+    print('File not found')
+    return 2
+end
+
+local radius = tonumber(file:read("*l"))
+
+if not radius then
+    print('Requires radius on the first line')
+    return 3
+end
+
+local rings = {}
+
+-- parse file:
+for line in file:lines() do
+    local ring = {}
+    for c in string.gmatch(line, ".") do
+        local n = tonumber(c)
+        if c == 'X' then
+            ring[#ring + 1] = c
+        elseif n then
+            ring[#ring + 1] = n
+        else
+            print('Invalid sequence: ' .. c)
+            return 4
+        end
+    end
+    rings[#rings + 1] = ring
+end
+
+file:close()
+
+local inverted = false
+
+robot.select(1)
+
+-- build:
+nav.forward(radius)
+robot.turnRight()
+for _, ring in ipairs(rings) do
+    for _ = 1, 4 do
+        inverted = false
+        for i, n in ipairs(ring) do
+            if n == 'X' then
+                robot.turnRight()
+                inverted = true
+            else
+                -- place sequence
+                for _ = 1, n do
+                    robot.placeDown()
+                    if robot.count() == 0 then
+                        robot.select(robot.select() + 1) -- select the next item slot
+                    end
+                    nav.forward()
+                end
+
+                if i ~= #ring then
+                    -- step level
+                    if not inverted then
+                        robot.turnRight()
+                        nav.forward()
+                        robot.turnLeft()
+                    else
+                        robot.turnLeft()
+                        nav.forward()
+                        robot.turnRight()
+                    end
+                end
+            end
+        end
+    end
+    robot.turnLeft()
+    nav.forward()
+    robot.turnRight()
+end
+
+robot.turnRight()
+nav.forward(radius + #rings)
+robot.turnAround()
diff --git a/rings b/rings
new file mode 100644
index 0000000..4637312
--- /dev/null
+++ b/rings
@@ -0,0 +1,6 @@
+25
+82222111X1122227
+82222111X11122227
+822221111X11122227
+83322211X1222337
+83322211X11222337