#include <stdio.h>

/* example of a while */

int main() {

	float r, a;
	const float PI = 3.141593;
	scanf("%f", &r);
	while (r != 0)
	{
		a = PI * r * r;
		printf("radius = %f area = %f\n", r, a);
		scanf("%f", &r);
	}

}