PROGRAMMING:Fast summation

Please write a program, input integer $$n $$, fast calculation:
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####Input format
> $$n$$
####Output format
> $$s$$
Requirements: output 5 decimal places, round the last place.
####Input sample 1
```in
four
```
####Output sample 1
```out
zero point eight zero zero zero zero
```
####Input sample 2
```
three hundred
```
####Output sample 2
```
zero point nine nine six six eight
```







answer：If there is no answer, please comment
This problem should not be written cycle, should simplify the formula, direct calculation solution.