// Geometry Templates>>>>>>>>>>>>

#include<stdio.h>

#include<string.h>

#include<vector>

#include<math.h>

#include<algorithm>

using namespace std;

//Macro........

#define maxm 100100

#define pi acos(-1.0)

#define eps 1e-9

#define sq(a) ((a)*(a))

#define dist(a,b) (sq(a.x-b.x) + sq(a.y-b.y))

#define iseq(a,b) (fabs(a-b)<eps)

#define mini(a,b) a<b ? a:b

#define maxi(a,b) a>b ? a:b

#define area_t(x1,y1,x2,y2,x3,y3) ( x1*(y2-y3) + x2*(y3-y1) + x3*(y1-y2) )

#define spDist(lat1,long1,lat2,long2,r) ( r * acos( sin(lat1) * sin(lat2) + cos(lat1) * cos(lat2) * cos(long1-long2) ) )

// Template........

template< class T > bool inside(T a, T b, T c) { return a<=b && b<=c; }

// Structure....

struct point { // Creates normal 2D point

double x, y;

point() {}

point( double xx, double yy ) { x = xx, y = yy; }

};

struct point3D { // Creates normal 3D point

double x, y, z;

};

struct line { // Creates a line with equation ax + by + c = 0

double a, b, c;

line() {}

line( point p1,point p2 ) {

a = p1.y - p2.y;

b = p2.x - p1.x;

c = p1.x * p2.y - p2.x * p1.y;

}

};

struct circle { // Creates a circle with point 'center' as center and r as radius

point center;

double r;

circle() {}

circle( point P, double rr ) { center = P; r = rr; }

};

struct segment { // Creates a segment with two end points -> A, B

point A, B;

segment() {}

segment( point P1, point P2 ) { A = P1, B = P2; }

};

inline double distancepp( point a, point b ) {

return sqrt( ( a.x - b.x ) * ( a.x - b.x ) + ( a.y - b.y ) * ( a.y - b.y ) );

}

inline double sq_distance( point a, point b ) {

return ( a.x - b.x ) * ( a.x - b.x ) + ( a.y - b.y ) * ( a.y - b.y );

}

inline double distancepl( point P, line L ) {

return fabs( L.a * P.x + L.b * P.y + L.c ) / sqrt( L.a * L.a + L.b * L.b );

}

inline double cross( point p0, point p1, point p2 ) {

return( ( p1.x - p0.x ) * ( p2.y - p0.y ) - ( p2.x - p0.x ) * ( p1.y - p0.y ) );

}

double areaPoly(point P[],int n){

double area=0;

for( int i = 0, j = n - 1; i < n; j = i++ ) area += P[j].x * P[i].y - P[j].y * P[i].x;

return fabs(area)*.5;

}

bool sort_x(point a,point b){

if(iseq(a.x,b.x)) return a.y<b.y;

return a.x<b.x;

}

bool sort_y(point a,point b){

if(iseq(a.y,b.y)) return a.x<b.x;

return a.y<b.y;

}

//end>>>>>

int n,nc;

point p[maxm],c[maxm]; // p=all points. c=convex_hull points

//comp = polar angle>>>(convex_hull)

bool comp(point a,point b){

double d = cross(p[0], a, b);

if(d<0) return false;

if(iseq(d,0) && dist(p[0], b) < dist(p[0], a)) return false;

return true;

}

void convex_hull(point c[],int &n,int &nc);

double ang(point a,point b,point c){ //returns angle <bac

double absq = sq_distance(a , b);

double bcsq = sq_distance(c , b), acsq = sq_distance(a , c);

double cosp = (absq+acsq - bcsq)/(2.0*sqrt(absq * acsq) );

return acos(cosp);

}

double conv(double theta){

double ret=180; ret/=pi; return ret*theta;

}

bool normal(const point &a, const point &b) { return (iseq(a.x,b.x) ? a.y < b.y : a.x < b.x);}

bool issame(const point &a, const point &b) { return (iseq(a.x,b.x) && iseq(a.y,b.y));}

void makeUnique(int &np) { sort(&p[0], &p[np], normal); np = unique(&p[0], &p[np], issame) - p;}

int main(){

int i,j,k,l,test,t=1;

// freopen("in.txt","r",stdin);

scanf("%d",&test);

while(test--){

scanf("%d",&n);

for(i=0;i<n;i++){

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

}

if(n<3){

printf("Case %d: %lf\n",t++,0);

continue;

}

nc=0;

convex_hull(c,n,nc);

if(nc<3){

printf("Case %d: %lf\n",t++,0);

continue;

}

double ans=1000,temp;

for(i=0;i<nc;i++){

temp=ang(c[(i+1)%nc],c[i],c[(i+2)%nc]);

if(temp<ans) ans=temp;

}

printf("Case %d: %lf\n",t++,conv(ans));

}

return 0;

}

void convex_hull(point ans[],int &n,int &nc){

makeUnique(n);

int i,pos = 0;

for(i=1; i<n; i++)

if(p[i].y<p[pos].y || (p[i].y==p[pos].y && p[i].x<p[pos].x))

pos = i;

swap(p[0], p[pos]);

sort(p+1, p+n, comp);

ans[0] = p[0];

if(n>=2) ans[1] = p[1];

for(i=nc=2; i<n; i++)

{

while(nc>=2 && cross(ans[nc-2], ans[nc-1], p[i])<0||iseq(cross(ans[nc-2], ans[nc-1], p[i]),0)) nc--;

ans[nc++] = p[i];

}

if(n==1) nc=1;

else if(nc==2)

{

if(p[0].x == p[1].x && p[0].y == p[1].y) nc=1;

}

}