The plane denoted by P1:4x+7y+4z+81=0 is rotated through a right angle about its line of intersection with the plane P2:5x+3y+10z=25 . If the plane in its new position be denoted by P , and the distance of this plane from the origin is d , then the value of [2k] (where [.] represents greatest integer less than or equal to k ) is .....