PROGRAMMING:Elephants drink water
###Task description
An elephant is thirsty and needs to drink 20 liters of water to quench his thirst, but now there is only a small barrel with a depth of HCM and a bottom radius of RCM (both h and R are integers). Ask the elephant at least how many barrels of water it needs to drink to quench its thirst.
###Input format:
Input has one line: package line, two integers, separated by a space, respectively represent the depth h and bottom radius r of the small barrel, both in cm.
###Output format:
Output a line containing an integer indicating the number of buckets the elephant needs to drink at least.
###Input example:
```in
23 11
```
###Output example:
```out
three
```
###Tips
If the depth of a barrel is HCM and the bottom radius is RCM, it can hold at most pi * r * r * HCM of water（ Let pi = 3.14159)
1 liter = 1000 ml
1 ml = 1 cc
Note: this topic is selected from openjudge website http://noi.openjudge.cn/ch0103/14/ .
answer：If there is no answer, please comment
An elephant is thirsty and needs to drink 20 liters of water to quench his thirst, but now there is only a small barrel with a depth of HCM and a bottom radius of RCM (both h and R are integers). Ask the elephant at least how many barrels of water it needs to drink to quench its thirst.
###Input format:
Input has one line: package line, two integers, separated by a space, respectively represent the depth h and bottom radius r of the small barrel, both in cm.
###Output format:
Output a line containing an integer indicating the number of buckets the elephant needs to drink at least.
###Input example:
```in
23 11
```
###Output example:
```out
three
```
###Tips
If the depth of a barrel is HCM and the bottom radius is RCM, it can hold at most pi * r * r * HCM of water（ Let pi = 3.14159)
1 liter = 1000 ml
1 ml = 1 cc
Note: this topic is selected from openjudge website http://noi.openjudge.cn/ch0103/14/ .
answer：If there is no answer, please comment