/* To find the area of perimeter  */
/* formula: 2 pi r  */
#include< stdio.h>
#include< conio.h>
# define pi 3.14         /* preprocessor */
main()
{
	int radius,*rr;
	float temp,*result;
	clrscr();
	scanf("%d",&radius);
	rr=radius;
	result=&temp;
	*rr=3;
	*result=pi * *rr;
	printf("\n Perimeter=%f",*result);
	getch();
}