#include <stdio.h>
#include <math.h>
int main()
{
double area;
double a, b, c;
scanf("%lf", &area);
c=area*100/314;
printf("%.2lf ", sqrt(c));
return 0;
}
#include <stdio.h>
#include <math.h>
int main()
{
double area;
double a, b, c;
scanf("%lf", &area);
c=area*100/314;
printf("%.2lf ", sqrt(c));
return 0;
}
