int N;
Point ppx[110];
int main() {
	scanf("%d",&C.n);
	N=C.n;
	for(int i=0;i<C.n;i++) {
		ppx[i].input();
	}
	ppx[C.n]=ppx[0];
	double l=eps,r=2.0*acos(-1)/N;
	while(r-l>1e-15) {
		double mid=(l+r)/2;
		for (int i=0;i<C.n;i++) {
			C.c[i].r=(ppx[i].distance(ppx[i+1])/2/sin(mid));
			double dtmp=C.c[i].r*cos(mid);
			Point ptmp=(ppx[i]+ppx[i+1])/2;
			Point pptmp=(ppx[i]-ptmp);
			pptmp=pptmp.rotright();
			pptmp=pptmp.trunc(dtmp);
			ptmp=ptmp+pptmp;
			C.c[i].p=ptmp;
		}
		C.getarea();
		if(C.ans[C.n]>1e-20)l=mid;
		else r=mid;
	}
	printf("%.20lf\n",l*180/pi);
	return 0;
}