Time Limit: 1000 MS Memory Limit: 65536 K

## Description

Give you N sawthooth lines.
The length of each sawtooth line is infinity.
We use these sawtooth lines to divide up the plane.
How many parts at most can be divided up.
The following figure show the case of N=2.
## Input

There are multiply test cases.
For each test case:
There is only one line contains only one integer N.
0 <= n < 10^{9}
## Output

For each test case output the answer on a single line.
## Sample Input

2
3
## Sample Output

7
16
## Source

8th SCUPC
## Author

baoer