P3908 XOR of a Sequence

Description

Find the value of $1 \oplus 2 \oplus\cdots\oplus N$. $A \oplus B$ denotes the bitwise XOR of $A,B$.

Input Format

One line with an integer $N$.

Output Format

One integer, the answer.

Explanation/Hint

- For 50% of the testdata, $1 \le N \le 10^6$. - For 100% of the testdata, $1 \le N \le 10^{18}$. Translated by ChatGPT 5