• Start from M_RRURmRvRvRmU
• Close the bridge on one side (west) and rotate 90 degrees clockwise in order to obtain a 3x2 rectangle with a stack of three tiles in the North-East position with the top one (third floor) of type slash and connected to the Central-East tile
• Open by hinging the stack about the South side (first-second floor) and the East side (second-third floor) into the final shape