include[HTML_REMOVED]
using namespace std;
double n;
int main()
{
scanf(“%lf”,&n);
double l,r,mid;
if(n>=1) l=1.0,r=n;
else if(n<=-1) l=n,r=-1;
else l=-1,r=1;
while(r-l>10e-8)
{
mid=(l+r)/2;
if(midmidmid>=n) r=mid;
else l=mid;
}
printf(“%lf”,l);
return 0;
}