#include<iostream>
using namespace std;
int n,i,j,k,ans;
bool judge(int j)
{
	int all=n*2,w=j%all;
	for(k=1;k<n;k++)
	{
		w=w+j-all;
		all--;
		w=w%all;
		if(w==0)w=all;
	if(w<=n)
		return false;
	}
	return true;
}
int main()
{
	while(scanf("%d",&n)&&n!=0)
		for(i=n+1;;i+=(i%n==0?n+1:1))
			if(judge(i))
			{
				printf("%d\n",i);break;
			}
	return 0;
}