## Using Reduce

### Instruction

Create three functions :
- `adder` that receives an array and adds its elements.

- `sumOrMul` that receives an array and adds or multiplies its elements
depending on whether the element is an odd or an even number.

- `funcExec` that receives an array of functions and executes them.

All functions may or may not receive an extra argument that should be the
initial value for the functions execution.

Example:
```js
sumOrMul([1, 2, 3, 4], 5)
  // -> (((5 + 1) * 2) + 3) * 4
  // -> 60
````


### Notions

- https://devdocs.io/javascript/global_objects/array/reduce