import java.util.*;
import java.lang.*;
import java.io.*;
class Ideone
{
{
Scanner in
= new Scanner
(System.
in); double x,n,s=0;
n=in.nextDouble();
x=in.nextDouble();
for (int i=0; i<n; i++){
}
System.
out.
printf("S = %f",s
); }
}
aW1wb3J0IGphdmEudXRpbC4qOwppbXBvcnQgamF2YS5sYW5nLio7CmltcG9ydCBqYXZhLmlvLio7CgpjbGFzcyBJZGVvbmUKewoJcHVibGljIHN0YXRpYyB2b2lkIG1haW4gKFN0cmluZ1tdIGFyZ3MpIHRocm93cyBqYXZhLmxhbmcuRXhjZXB0aW9uCgl7CgkJU2Nhbm5lciBpbiA9IG5ldyBTY2FubmVyKFN5c3RlbS5pbik7CgkJZG91YmxlIHgsbixzPTA7CgkJbj1pbi5uZXh0RG91YmxlKCk7CgkJeD1pbi5uZXh0RG91YmxlKCk7CgkJZm9yIChpbnQgaT0wOyBpPG47IGkrKyl7CgkJCXMrPSh4PU1hdGguc2luKHgpKTsKCQl9CgkJU3lzdGVtLm91dC5wcmludGYoIlMgPSAlZiIscyk7Cgl9Cn0=