#include<stdio.h>
double diameter(double radius)
{
    return (2*radius);
}
double circumference(double radius)
{
    return (2*PI*radius);

}
double area(double radius)
{
    return (2*radius*radius);
}
int main()
{
    double are,circ,dia,radi;
    scanf("%lf",&radius);
    printf("%d\n",radius of the circle);
    dia=diameter(radius);
    circ=circumference(radius);
    are=area(radius);
    printf("Diameter of the circle=%lf\n",dia);
    printf("Circumference of the circle=%lf\n",circ);
    printf("Area of the circle=%lf\n",are);
    return 0;

}