class point{
	int x,y;
	void cs(int a,int b){
		x=a;y=b;
		}
	}
	
class circle{
	point center;
	int radius;
	circle(int a,int b,int r){center.x=a;center.y=b;radius=r;
		}
	}
	
public class yuanlei{
	public static void main(String[] args)
	{
		circle area=new circle(0,0,5);	
		System.out.print("the area is:"+3.14*area.radius*area.radius);
		}
	}