PROGRAMMING:Finding the sum of the first n terms of the square root sequence
This problem requires the preparation of procedures to calculate the sum of the first n terms of the square root sequence $$\ sqrt {1} + \ sqrt {2} + \ \ sqrt {3} + \ \ cdots $$. You can include the header file 'math. H' and call the 'sqrt' function to find the square root.
###Input format:
The input gives a positive integer n on one line.
###Output format:
In one line, output the value s of partial sum in the format of "sum = s", accurate to two decimal places. The calculation results should not exceed the double precision range.
###Input example:
```in
ten
```
###Output example:
```out
sum = 22.47
```
answer：If there is no answer, please comment
###Input format:
The input gives a positive integer n on one line.
###Output format:
In one line, output the value s of partial sum in the format of "sum = s", accurate to two decimal places. The calculation results should not exceed the double precision range.
###Input example:
```in
ten
```
###Output example:
```out
sum = 22.47
```
answer：If there is no answer, please comment