Four identical triangles were cut away from a rectangular cardboard EFGH of length 42 cm and breadth 18 cm, as shown in the figure below. <hr> Given that JG is $$\frac{1}{6}$$ of HG and GK is $$\frac{1}{3}$$ of GF, area of the remaining cardboard = <input min="0" type="number" id ="imp5pg085q5_1" class="lineinput" placeholder="?" /> $$cm^2$$.