#include <math.h>
#include <stdio.h>
#define EPS 3.0e-11

void gauleg(float x1,float x2, double x[],double w[],int n)
{
	int m,j,i;
	double z1,z,xm,xl,pp,p3,p2,p1;
	m=(n+1)/2;
	xm=0.5*(x2+x1);
	xl=0.5*(x2-x1);
	for (i=1;i<=m;i++) {
		z=cos(M_PI*(i-0.25)/(n+0.5));
		do {
			p1=1;
			p2=0;
			for (j=1;j<=n;j++) {
				p3=p2;
				p2=p1;
				p1=((2*j-1)*z*p2-(j-1)*p3)/j;
			}
			pp=n*(z*p1-p2)/(z*z-1);
			z1=z;
			z=z1-p1/pp;
		} while (fabs(z-z1) > EPS);
		x[i]=xm-xl*z;
		x[n+1-i]=xm+xl*z;
		w[i]=2*xl/((1-z*z)*pp*pp);
		w[n+1-i]=w[i];
	}
}

double F(double x,int xp,int yp,double y[],double w[],int n)
{
	double s;int i;
	for (i=1;i<=n;i++) {
		s+=w[i]*1/sqrt(pow((x-xp),2)+pow((y[i]-yp),2));
		/*printf("%le %d %d %le\n",w[i],xp,yp,y[i]);*/}
	//printf ("%le %le\n",x,s);
	return s;
}

void main()
{
	FILE *stream;
	int n,i;
	int xp,yp;
	double s=0,s2=0;
	char datei[50];
	printf("xp: ");scanf("%d",&xp);
	printf("yp: ");scanf("%d",&yp);
	printf("n: "); scanf("%d",&n);
	//printf("Ausgabedateiname: "); scanf("%s",datei);
	double x[n];double w[n];
	/*if ((stream=fopen(datei,"w"))==NULL)
		{
			printf("Kann Datei nicht öffnen!!!");
			exit(1);
		}*/
	gauleg(-1,1,x,w,n);
	
	for (i=1;i<=n;i++) {
		s2=F(x[i],xp,yp,x,w,n);
		s+=w[i]*s2;printf("%le",s2);}
	
	printf("\n%1.10lf\n",s);
	//fprintf(stream,"%1.10le",s);
}