#include<cstdio>

#include<iostream>

#include<cstdlib>

#include<algorithm>

#include<cmath>

#define N 1010

#define eps 1e-7

using namespace std;

int x,y,n;double r;

struct node{

    double x,y;

};node p[N],c;

double dis(node i,node j){

    return sqrt((i.x-j.x)*(i.x-j.x)+(i.y-j.y)*(i.y-j.y));

}

node get(node p1,node p2,node p3){

    node t;

    double c1=(p1.x*p1.x-p2.x*p2.x+p1.y*p1.y-p2.y*p2.y)/2.0;

    double c2=(p3.x*p3.x-p2.x*p2.x+p3.y*p3.y-p2.y*p2.y)/2.0;

    t.x=(c1*(p3.y-p2.y)-c2*(p1.y-p2.y))/((p1.x-p2.x)*(p3.y-p2.y)-(p3.x-p2.x)*(p1.y-p2.y));

    t.y=(c1*(p3.x-p2.x)-c2*(p1.x-p2.x))/((p1.y-p2.y)*(p3.x-p2.x)-(p3.y-p2.y)*(p1.x-p2.x));

    return t;

}

void work(){

    random_shuffle(p,p+n);

    c=p[];r=;

    for(int i=;i<n;i++)

        if(dis(c,p[i])+eps>r){

            c=p[i];r=;

            for(int j=;j<i;j++)

                if(dis(c,p[j])+eps>r){

                    c.x=(p[i].x+p[j].x)/;//不知道为啥这里写成c.x=(c.x+p[j].x)/2就WA了

                    c.y=(p[i].y+p[j].y)/;

                    r=dis(c,p[j]);

                    for(int k=;k<j;k++)

                        if(dis(c,p[k])+eps>r){

                            c=get(p[i],p[j],p[k]);

                            r=dis(c,p[k]);

                        }

                }

        }

        printf("(%.1lf,%.1lf).\n%.1lf\n",c.x,c.y,r);

}

int main(){

    while(cin>>x>>y>>n){

        for(int i=;i<n;i++)

            scanf("%lf%lf",&p[i].x,&p[i].y);

        work();

    }

    return ;

}

Point circumcenter(const Point &a,const Point &b,const Point &c)

{

    Point ret;

    double a1=b.x-a.x,b1=b.y-a.y,c1=(a1*a1+b1*b1)/;

    double a2=c.x-a.x,b2=c.y-a.y,c2=(a2*a2+b2*b2)/;

    double d=a1*b2-a2*b1;

    ret.x=a.x+(c1*b2-c2*b1)/d;

    ret.y=a.y+(a1*c2-a2*c1)/d;

    return ret;

}