#include<cstdio>#include<cmath>#include<algorithm>using namespace std;typedef double ld;int n;const ld pi=acos(-1.l),_2pi=pi*2;struct itv{ld l,r;};bool operator<(itv x,itv y){return x.l<y.l;}int ip=0;ld ans=0;void maxs(ld&a,ld b){if(a<b)a=b;}itv is[2007];struct cir{    ld x,y,r;    void init(){        scanf("%lf%lf%lf",&r,&x,&y);    }    bool in(cir w){        ld a=x-w.x,b=y-w.y;        return sqrt(a*a+b*b)+r-1e-8<w.r;    }    bool cross(cir w){        ld a=x-w.x,b=y-w.y;        ld c=sqrt(a*a+b*b);        return c<r+w.r-1e-8&&c>fabs(r-w.r)+1e-8;    }    ld fix(ld x){        while(x<0)x+=_2pi;        while(x>_2pi)x-=_2pi;        return x;    }    void cal(cir w){        ld xd=w.x-x,yd=w.y-y,d=sqrt(xd*xd+yd*yd);        ld a=atan2(yd,xd);        ld b=acos((r*r+d*d-w.r*w.r)/(2*r*d));        ld l=fix(a-b),r=fix(a+b);        if(l<r)is[ip++]=(itv){l,r};        else is[ip++]=(itv){0,r},is[ip++]=(itv){l,_2pi};    }    void get(){        std::sort(is,is+ip);        ld L,R,s=_2pi;        for(int i=0,j=0;i<ip;i=j){            L=is[i].l;R=is[i].r;            while(j<ip&&is[j].l<=R)maxs(R,is[j++].r);            s-=R-L;        }        ans+=s*r;    }}cs[1007];int main(){    scanf("%d",&n);    for(int i=0;i<n;++i)cs[i].init();    for(int i=0;i<n;++i){        ip=0;        for(int j=i+1;j<n;++j)if(cs[i].in(cs[j]))goto out;        for(int j=i+1;j<n;++j)if(cs[i].cross(cs[j]))cs[i].cal(cs[j]);        cs[i].get();        out:;    }    printf("%.3f",ans);    return 0;}