约瑟夫环wuwuwu

#include<bits/stdc++.h>
using namespace std;

int f(int n, int k)
{
    if(n == 1) return 0;
    return (f(n - 1, k) + k) % n;
}
int main()
{
    int n;
    cin >> n;

    cout << f(n, 3) + 1 << endl;
    return 0;
}