#include<bits/stdc++.h>
#define MAX 500003
 
using namespace std;
 
int store[MAX];
 
void solve()
{
    int i,ans=0;
 
    store[1] = 1;
 
    for(i=2; i<=500000; i++)
    {
        ans +=2;
 
        store[i] = ans;
 
        if(i==ans)
        {
            ans = 0;
        }
    }
}
 
int main()
{
    solve();
 
    int take;
 
    while(scanf("%d",&take)&&take)
    {
        printf("%d\n",store[take]);
    }
 
    return 0;
}