#include<bits/stdc++.h>
using namespace std;
int p[30]={0},k;
int find()
{
	int n=0;
	int end=0,i=1+k;//m>=k+1
	while(!end){
	    int location=0,judge=0;
	    for(int j=1;j<=k;j++)p[j]=1;
	    for(int j=k+1;j<=2*k;j++)p[j]=0; 
		while(n<k){
			location=(location+n)%(2*k-n);
			p[location]=-1;
			++n;
		}
		for(int j=1;j<=k;j++){
			if(p[j]!=1){
				judge=1;
				break;
			}
		}
		if(!judge){
			end=1;
			return i;
		}
		else ++i;
	}	
	return -1;
}
int main()
{
	scanf("%d",&k);
	printf("%d",find());
	return 0;
}
/*
111000
11100
1110
111
*/