#include <stdio.h>
int main()
{
    int s,n,d;
    while(scanf("%d",&s)!=EOF)
    {
        for(n=1;; n++)
        {
            if(n*(n+1)/2==s)
            {
                printf("%d\n",n);
                break;
            }
            else if(n*(n+1)/2>s)
            {
                d=n*(n+1)/2-s;
                if(d%2!=0)
                    continue;
                else
                    d/=2;
                if(d>=1)
                    printf("%d\n",n);
                break;
            }
        }
    }
    return 0;
}