• Start from M_RUUmDvUvLDmD
• Close both flaps against opposite sides (west and east) of the "tube"
• Move lower tile of the East wall towards the lonely tile of the south wall and change their hinging side
• Simultaneously push apart the two lower tiles of the West wall (also changing their hinging side, hence hinging about their upper side, some stretching involved)
• Finally open the flap to obtain the final shape.