#include<cstdio>

#include<cstring>

#include<algorithm>

#include<cmath>

#define db double

using namespace std;

const int N=; const db pi=acos(-),pi2=pi*;

int n;db x[N],y[N],r[N],rf[N],ans;

struct Node{

  db l,r;

  Node(db a=,db b=):l(a),r(b) {}

  bool operator< (const Node &b)const

  {return l<b.l;}

}a[N<<];

db Sqr(db x){return x*x;}

db dMx(db a,db b){return a>b?a:b;}

db Fix(db a){while(a>pi2)a-=pi2;while(a<)a+=pi2;return a;}

int main()

{

  scanf("%d",&n);

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

    scanf("%lf%lf%lf",&r[i],&x[i],&y[i]),rf[i]=r[i]*r[i];

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

    {

      int cnt=;bool flag=;

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

    {

      db d=Sqr(x[i]-x[j])+Sqr(y[i]-y[j]),sd=sqrt(d);

      if(sd>=r[i]+r[j]||r[j]+sd<=r[i])continue;

      if(r[i]+sd<=r[j]){flag=;break;}

      db fx=atan2(y[j]-y[i],x[j]-x[i]);

      db k=acos((rf[i]+d-rf[j])/(*r[i]*sd));

      db l=Fix(fx-k),r=Fix(fx+k);//Fix

      if(l<r)a[++cnt]=Node(l,r);

      else a[++cnt]=Node(,r),a[++cnt]=Node(l,pi2);

    }

      if(flag)continue;///

      sort(a+,a+cnt+);

      db ret=pi2;

      for(int x=,y;x<=cnt;x=y)

    {

      db R=a[x].r;

      for(y=x+;y<=cnt&&a[y].l<=R;y++)R=dMx(R,a[y].r);

      ret-=R-a[x].l;

    }

      ans+=r[i]*ret;

    }

  printf("%.3f\n",ans);

  return ;

}