#771. Squares on a board
How many squares of all sizes are there on an n×n board? (Example: a 2×2 board has 5.)
### Input
One integer n (1 ≤ n ≤ 100).
### Output
A number.
Examples
Input
19
Output
2470
Input
53
Output
51039
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.