题目描述
Problem Statement
Given is an integer N.
Find the minimum possible positive integer k such that $(1+2+\cdots+k)$ is a multiple of N.
It can be proved that such a positive integer k always exists.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer in a line.
Constraints
- $1 \leq N \leq 10^{15}$
- All values in input are integers.
Sample Input 1
11
Sample Output 1
10
$1+2+\cdots+10=55$ holds and 55 is indeed a multple of N=11.
There are no positive integers $k \leq 9$ that satisfy the condition, so the answer is k = 10.
Sample Input 2
20200920
Sample Output 2
1100144
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
11
样例输出
10