A thin uniformed rod of mass `m` and length `L` is hinged at one end and from other end a light string is attached. The string is wound over a frictionless pullely (having mass `2m`) and a block of mass `2m` is connected to string on other side of pulley as shown. the system is released from rest when the rod id making an angle of `37^(@)` with horizontal. Based on above information answer the following question :

Just after releases of the system from rest acceleration of block is