#include<iostream>
using namespace std;
int main(){
	int m,n,i,j,k,x;
	cin>>k;
	while(k>0&&k<14){
		for(m=2;;m++){
			n=2*k;j=1;
			for(i=1;i<=k;i++){
				x=(m+j-1)%n;
				if(x<=k&&x>0) break;
				n--;
				if(x==0)j=1;
				else j=x;
			}
			if(i==k+1) {cout<<m<<endl;break;}
		}
		cin>>k;
	}
	return 0;
}