9545: ABC239 —— A - Horizon
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Description
Assuming that the horizon seen from a place $x$ meters above the ground is $\sqrt{x(12800000+x)}$ meters away, find how many meters away the horizon seen from a place $H$ meters above the ground is.
Input
Input is given from Standard Input in the following format:
```
$H$
```
```
$H$
```
Output
Print the answer.
Your answer will be considered correct when the absolute or relative error from the judge's answer is at most $10^{-6}$.
Your answer will be considered correct when the absolute or relative error from the judge's answer is at most $10^{-6}$.
Constraints
- $1 \leq H \leq 10^5$
- $H$ is an integer.
- $H$ is an integer.
Sample 1 Input
333
Sample 1 Output
65287.907678222
We have $\sqrt{333(12800000+333)}=65287.9076782…$ Outputs such as 65287.91 would also be accepted.
Sample 2 Input
634
Sample 2 Output
90086.635834623
We have $\sqrt{634(12800000+634)}=90086.6358346…$