|-------7x------| |-------5x------|
|x x x x x x x x|x x x x x x x x |x x x x x x x x|x x x x x x x x |
| s s ss s| s s s s | s s ss s| s s s s |
|o o o o |o o o o o|o o o o |o o o o o|
|-------2x------|-------4x------|-------3x------|
|x x x x x x x x|x x x x x x x x|x x x x x x x x|x x x x x x x x |
| s s ss s| s s s s| s s ss s| s s s s |
|o o o o |o o o o |o o o o |o o o o o|
|-------2x------|-------5x------| |-------3x------|
| | | O | |
|x x x x x x x x|x x x x x x x x|x x x x x |x x x x x x x x|
| s s ss s| s s s s| s s | s s ss s|
|o o o o |o o o o |o o o o |o o o o |
|-------4x------|
|x x x x x x x x|x x x x x x x x|
| s s s s| s s ss s|
|o o o o |o o o o |