#include <cstdio>#include <cstring>#include <cmath>#include <string>#include <iostream>#include <algorithm>#include <queue>#include <set>#include <map>#include <sstream>using namespace std;typedef long long ll;#define pb push_back#define rep(i, n) for(int i=0; i<(n); ++i)#define for1(i,a,n) for(int i=(a);i<=(n);++i)#define for2(i,a,n) for(int i=(a);i<(n);++i)#define for3(i,a,n) for(int i=(a);i>=(n);--i)#define for4(i,a,n) for(int i=(a);i>(n);--i)#define CC(i,a) memset(i,a,sizeof(i))#define read(a) a=getint()#define print(a) printf("%d", a)#define dbg(x) cout << (#x) << " = " << (x) << endl#define error(x) (!(x)?puts("error"):0)#define rdm(x, i) for(int i=ihead[x]; i; i=e[i].next)inline int getint() { static int r, k; r=0,k=1; static char c; c=getchar(); for(; c<‘0‘||c>‘9‘; c=getchar()) if(c==‘-‘) k=-1; for(; c>=‘0‘&&c<=‘9‘; c=getchar()) r=r*10+c-‘0‘; return k*r; }const double eps=1e-6, PI=acos(-1);int dcmp(double x) { return abs(x)<eps?0:(x<0?-1:1); }double sqr(double x) { return x*x; }struct iP { double x, y; iP(double _x=0, double _y=0) : x(_x), y(_y) {} };double dis(iP &a, iP &b) { return sqrt(sqr(a.x-b.x)+sqr(a.y-b.y)); }struct iC {	iP p; double r;	iP getP(double d) { return iP(p.x+cos(d)*r, p.y+sin(d)*r); }	double areaH(double d) { return (d-sin(d))/2*sqr(r); }};double angle(iP &a, iP &b) {	static double x, y;	x=b.x-a.x; y=b.y-a.y;	return atan2(y, x);}void CCi(iC &a, iC &b, double &ang1, double &ang2) {	static double ang, d, R, r, da;	d=dis(a.p, b.p); //dbg(d);	ang=angle(a.p, b.p);	R=a.r; r=b.r; //dbg((sqr(R)+sqr(d)-sqr(r))/2/R/d);	da=acos((sqr(R)+sqr(d)-sqr(r))/2/R/d);	ang1=ang-da;	ang2=ang+da;}const int N=1105;iC a[N];int n, cnt;bool nok[N];struct dat { double pos; int k; }b[N*5];bool cmp(const dat &a, const dat &b) { return a.pos<b.pos; }int main() {	read(n);	for1(i, 1, n) scanf("%lf%lf%lf", &a[i].p.x, &a[i].p.y, &a[i].r);	for1(i, 1, n) for1(j, 1, n) if(!nok[j] && i!=j) {		double d=dis(a[i].p, a[j].p);		if(dcmp(a[j].r-a[i].r-d)>=0) { nok[i]=1; break; }	}	double ang1, ang2, PI2=PI*2, ans=0;	int sum=0;	iP A, B;	for1(i, 1, n) if(!nok[i]) {		cnt=0;		for1(j, 1, n) if(i!=j && !nok[j]) {			if(dcmp(dis(a[i].p, a[j].p)-a[i].r-a[j].r)>=0) continue;			CCi(a[i], a[j], ang1, ang2);			if(dcmp(ang1)<0) ang1+=PI2;			if(dcmp(ang2)<0) ang2+=PI2;			if(dcmp(ang1-ang2)>0) {				++cnt; b[cnt].pos=0; b[cnt].k=1;				++cnt; b[cnt].pos=ang2; b[cnt].k=-1;				++cnt; b[cnt].pos=ang1; b[cnt].k=1;				++cnt; b[cnt].pos=PI2; b[cnt].k=-1;			}			else {				++cnt; b[cnt].pos=ang1; b[cnt].k=1;				++cnt; b[cnt].pos=ang2; b[cnt].k=-1;			}		}		++cnt; b[cnt].pos=0; b[cnt].k=0;		++cnt; b[cnt].pos=PI2; b[cnt].k=0;		sort(b+1, b+1+cnt, cmp);		sum=0;		for1(j, 1, cnt-1) {			sum+=b[j].k;			if(!sum) {				ans+=a[i].areaH(b[j+1].pos-b[j].pos);				A=a[i].getP(b[j].pos);				B=a[i].getP(b[j+1].pos);				ans+=(A.x*B.y-A.y*B.x)/2;			}		}	}	printf("%.3f\n", ans);	return 0;}