PROGRAMMING:2/1+3/2+5/3+...
Find the sum of the first 20 items of the following fractional sequence.
。
###Output format:
Directly output the result with 2 decimal places, without any additional characters.
###Output example:
```out
thirty-two point six six
```
answer：If there is no answer, please comment
。
###Output format:
Directly output the result with 2 decimal places, without any additional characters.
###Output example:
```out
thirty-two point six six
```
answer：If there is no answer, please comment