It's that time of the year again: WINTER! It has just snowed and Derek's driveway is covered in snow. It's Derek's job to shovel the snow but he hates doing it because it delays him from programming. Given \(l\), \(w\), \(d\), and \(t\), help Derek calculate how much time is needed to clear his driveway so he can get back to coding the next big game.

\(l\), the length of his driveway in metres

\(w\), the width of his driveway in metres

\(d\), the depth of the snow in metres

\(t\), the time (seconds) it takes to shovel 1 cubic metre

#### Input Specification

There will be a 4 lines of input, \(l\), \(w\), \(d\), and \(t\).

\(1 \le l,w,d,t \le 10^5\)

#### Output Specification

Output one number, rounded to **exactly one decimal point**, the number of seconds it takes for Derek to clear his driveway

#### Sample Input

```
3
4
0.5
20
```

#### Sample Output

`120.0`

#### Sample Explanation

The dimensions of the snow on his driveway is \(3m * 4m * 0.5m\). It takes Derek 20 seconds per \(m^3\), so it takes him 120 seconds.

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