Attempted: 1

Write a function called `calculate`

which takes an input
string `expression`

and computes the given expression and
returns the values. The expression will only contain the four basic
athematic operations `+`

(addition), `-`

(subtraction), `*`

(multiplication), and `/`

(division). The expression may contain brackets `()`

to check
the order of operations. By default multiplication and division take
higher precedence than addition and subtraction. Unary operations will
not be used (for example `-2`

will not be used, but
`5 - 2`

will be used).

Examples:

```
Input: 5
Output: 5
```

```
Input: 2 + 3 * 4
Output: 14
```

```
Input: (2 + 3) * 4
Output: 20
```