PROGRAMMING:help him
Today, the math teacher left a simple math problem, but because hammer's math is too bad, we can only find the witty acmer to help him solve this problem.
The title goes like this: known π It is composed of various scores, i.e π= 4 * (1 / 1-1 / 3 + 1 / 5-1 / 7 + 1 / 9...), now give us an accurate number n, π The operation starts from the first item fraction until a certain item fraction is less than the precision n, then the operation is stopped and the output is finished π。
### Input format:
There are several groups of test data, each group input an n.
###Output format:
The output is obtained π。
### Input example:
Here is a set of inputs. For example:
```in
zero point zero one
zero point zero zero one
zero point zero zero zero one
```
###Output example:
The corresponding output is given here. For example:
```out
three point one two one five nine five
three point one three nine five nine three
three point one four one three nine three
```
answer：If there is no answer, please comment
The title goes like this: known π It is composed of various scores, i.e π= 4 * (1 / 1-1 / 3 + 1 / 5-1 / 7 + 1 / 9...), now give us an accurate number n, π The operation starts from the first item fraction until a certain item fraction is less than the precision n, then the operation is stopped and the output is finished π。
### Input format:
There are several groups of test data, each group input an n.
###Output format:
The output is obtained π。
### Input example:
Here is a set of inputs. For example:
```in
zero point zero one
zero point zero zero one
zero point zero zero zero one
```
###Output example:
The corresponding output is given here. For example:
```out
three point one two one five nine five
three point one three nine five nine three
three point one four one three nine three
```
answer：If there is no answer, please comment