#379. Sum of numbers divisible by 7
You get a positive integer n. Find the sum of all numbers from 1 to n that can be divided by 7.
### Input
One integer n (1 ≤ n ≤ 10000).
### Output
The sum.
Examples
Input
6997
Output
3496500
Input
2854
Output
581196
💡 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.