PROGRAMMING:Calculate pi value
Write a program to show the result of the following formula:
PI = 4 *(1 -1/3 +1/5 -1/7 +1/9 -1/11 +1/13).
Use 1.0 instead of 1 in the program.
###Input format:
nothing
###Output format:
The value of the formula
###Input example:
Here is a set of inputs. For example:
```in
```
###Output example:
The corresponding output is given here. For example:
```out
three point two eight three seven three eight four eight three seven three eight four eight four four
```
answer：If there is no answer, please comment
PI = 4 *(1 -1/3 +1/5 -1/7 +1/9 -1/11 +1/13).
Use 1.0 instead of 1 in the program.
###Input format:
nothing
###Output format:
The value of the formula
###Input example:
Here is a set of inputs. For example:
```in
```
###Output example:
The corresponding output is given here. For example:
```out
three point two eight three seven three eight four eight three seven three eight four eight four four
```
answer：If there is no answer, please comment