Assemble a formula using the numbers $3$, $4$ and $6$ in any order to make 108.
You may use the operations;
$x + y$
$x - y$
$x \times y$
$x \div y$
- Brackets to clarify order of operations "(",")"
- Concatenate two or more of the three digits you start with (concatenation of numbers from calculations is not permitted)
as long as all operands are either $3$, $4$ and $6$.
Note that double, triple, etc. factorials (n-druple-factorials) are not allowed though factorials of factorials are fine, such as $((6-3)!)! = 6!$.