Write a haskell function called mergeTrees that takes as input two trees t$1$ and t$2$ and returns a tree t$3$ containing all of the values in t$1$ and t$2.$ example mergeTrees tree$1$ tree$2$

Node $5($Node $2$ Leaf $($Node $3$ Leaf Leaf$))($Node $7($Node $6$ Leaf Leaf$)($Node $8$ Leaf Leaf$))$