29. As shown in the figure, in trapezoid $A B C D$, $E F$ and $M N$ are both parallel to the bases, and $A B: C D=1: 2, C E$ : $E M: M B=1: 2: 3$. If the total area of the shaded parts is 10, then the area of trapezoid $A B C D$ is
$18$