#include <algorithm>
#include <bitset>
#include <cctype>
#include <complex>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
 
using namespace std;
 
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}
template<class T> inline T sqr(T x) {return x*x;}
 
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<string> vs;
typedef pair<int, int> pii;
typedef long long ll;
 
#define all(a)  (a).begin(),(a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define pb push_back
#define mp make_pair
#define each(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define exist(s,e) ((s).find(e)!=(s).end())
#define range(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n)  range(i,0,n)
#define clr(a,b) memset((a), (b) ,sizeof(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
 
 
const double eps = 1e-7;
const double pi  = acos(-1.0);
const ll INF =1LL << 62;
const int inf =1 << 30;
 
 
// 以下 幾何部分
template<class T> bool operator==(T a, T b){return abs(a-b)< eps;}
template<class T> bool operator< (T a, T b){return a < b-eps;}
template<class T> bool operator<=(T a, T b){return a < b+eps;}
template<class T> int sig(T r) {return (r==0||r==-0) ? 0 : r > 0 ? 1 : -1;}
#define X real()
#define Y imag()
#define mp make_pair
 
typedef bool B;
typedef long double D;
typedef complex<D> P;
typedef vector<P> VP;
typedef pair <P,P> L;
typedef pair <D,D> pdd;
typedef vector<L> VL;
typedef struct {P c;D r;} C;
typedef struct {P c;D a,b;} E; // 楕円も追加予定
typedef vector <P> Pol;
 
// ソートのキー
B cmp_x(const P &a,const P &b){ return (abs(a.X-b.X)<eps ) ?  a.Y<b.Y : a.X<b.X;}  // base x
B cmp_y(const P &a,const P &b){ return (abs(a.Y-b.Y)<eps ) ?  a.X<b.X : a.Y<b.Y;}  // base y
B cmp_a(const P &a,const P &b){ return (abs(arg(a)-arg(b))<eps ) ?  norm(a) < norm(b) : arg(a)<arg(b);} // base arg
 
 
// 基本操作
// verify
D ip(P a, P b) {return a.X * b.X + a.Y * b.Y;}
D ep(P a, P b) {return a.X * b.Y - a.Y * b.X;}
D sr(D a) {return sqrt(max(a, (D)0));}
P vec(L l){return l.second-l.first;}
 
 
// 点
D toRagian(D degree){ return degree*pi/180.0;}
D ang (P p){return arg(p);}
D ang (P base, P a, P b) {return arg( (b - base) / (a - base) );} // base 中心
P rot (P base, P a, D theta){return base+polar( abs(a-base), arg(a-base)+theta );}
 
 
// ccw 
enum CCW{FRONT = 1, RIGHT = 2, BACK = 4, LEFT = 8, MID = 16, ON=FRONT|BACK|MID };
 
inline int ccw(P base, P a, P b) {              //点aと点bが与えられた問いに
  a -= base; b -= base;
  if (ep(a, b) > eps)     return LEFT;    // counter clockwise
  if (ep(a, b) < -eps)      return RIGHT;   // clockwise
  if (ip(a, b) < 0)      return BACK;    // b--base--a on line
  if (norm(a) < norm(b)) return FRONT;   // base--a--b on line
                         return MID;      // base--b--a on line  aとbの線分判定はこれ
}
 
// 線分 直線
    // 点と直線の距離
    // 点と線分の距離
    // 直線と直線の距離
     
 
B iver(L a, L b) {return ip(vec(a),vec(b) )== 0.0;}
B ipar(L a, L b) {return ep(vec(a),vec(b) )== 0.0;}
 
 
// 交点
P pLL(L a,L b){ return a.first+vec(a)*ep(vec(b),b.first-a.first)/ep(vec(b), vec(a));}
 
 
// 点と直線と線分関連の交差判定
 
B iLL(L l1,L l2){ return !ipar(l1,l2);}
B eqL(L a, L b) {return !iLL(a, b) && ep(vec(a), b.first - a.first)==0;}
B iLS(L a, L b)  {return sig(ep(vec(a), b.first - a.first)) * sig(ep(vec(a), b.second - a.first)) <= 0;}
B iLSs(L a, L b) {return sig(ep(vec(a), b.first - a.first)) * sig(ep(vec(a), b.second - a.first)) <  0;}
B iSS(L a, L b) {
    int cwa = ccw(a.first,a.second, b.first) | ccw(a.first,a.second, b.second);
    int cwb = ccw(b.first,b.second, a.first) | ccw(b.first,b.second, a.second);
    return ((cwa | cwb) & MID) || ((cwa & cwb) == (LEFT | RIGHT));
}
B iSSs(L a, L b) {
    int cwa = ccw(a.first,a.second, b.first) | ccw(a.first,a.second, b.second);
    int cwb = ccw(b.first,b.second, a.first) | ccw(b.first,b.second, a.second);
    return (cwa & cwb) == (LEFT | RIGHT);
}
 
// 点と直線と線分関連の距離
 
D dLP(L l,P p){ return abs( ep(vec(l),p-l.first) )/abs(vec(l));}
D dSP(L s,P p){
    if (sig( ip( vec(s), p - s.first)) <= 0) return abs(p - s.first);
    if (sig( ip(-vec(s), p - s.second)) <= 0) return abs(p - s.second);
    return dLP(s,p);
}
D dLL(L a,L b){ return iLL(a,b) ? 0 : dLP(a,b.first);}
D dLS(L a,L b){ return iLS(a,b) ? 0 : min(dLP(a, b.first), dLP(a, b.second));}
D dSS(L a,L b){ return iSS(a,b) ? 0 : min( min(dSP(a,b.first),dSP(a,b.second)),min(dSP(b,a.first),dSP(b,a.second)));}
 
 
int n,m,k;
 
P col[52];
 
P star[52];
 
vector<pdd> in; 
P in2[110];
 
bool in_magic(D r,P c,P p){
    if(p==c) return true;
  
    D phi=ang(p-c),d=abs(p-c);
    if(d>r+eps) return false;
  
    if(phi<in[0].first+eps) phi+=2*pi;
    int i=upper_bound(in.begin(),in.end(),pdd(phi,0.0))-in.begin()-1;
    return ccw(r*in2[i],r*in2[(i+1)%in.size()],p-c)!=RIGHT;
}
 
bool check(D r,P a,P b){
    //dump(r)
    L seg1[52];
    L seg2[52];
 
    rep(i,m){
        L cur;
        cur.first=r*P(star[i].X,-star[i].Y); 
        cur.second=r*P(star[(i+k)%m].X ,-star[(i+k)%m].Y);
        seg1[i]=seg2[i]=cur;
        seg1[i].first+=a;seg1[i].second+=a;
        seg2[i].first+=b;seg2[i].second+=b;
    }

    VP stars(55*55);
    int sz=0;
    rep(i,m)rep(j,m){
        if(iSS(seg1[i],seg2[j]))
            stars[sz++]=(pLL(seg1[i],seg2[j]));
    }
    stars[sz++]=(P(0,0));
 
    rep(i,sz){
        bool ok=true;
        rep(j,n){
            if(!in_magic(r,stars[i],col[j])){
                ok=false;
                break;
            }
        }
        if(ok)
            return true;
    }
    return false;
}
 
int main(void){
    while(cin >> n >> m >> k,n|m|k){
        D ans=10000;
 
        rep(i,n)
            cin >> col[i].X >> col[i].Y;
 
        rep(i,m){
			 star[i].X=cos(2*i*pi/m+pi/2);
			 star[i].Y=sin(2*i*pi/m+pi/2);
  		}
		in.clear();
        rep(i,m){
            in.pb(pdd(ang(star[i]),abs(star[i])));
            if(k>1){
                L S1=L(star[i],star[(i+k)%m]);
                L S2=L(star[(i+1)%m],star[(i+1-k+m)%m]);
                if(iSS(S1,S2)){
                    P p=pLL(S1,S2);
                    in.pb(pdd(ang(p),abs(p)));
                }
            }
        }
 
        sort(in.begin(),in.end());
        rep(i,in.size()){
            in2[i].X=in[i].second*cos(in[i].first);
			in2[i].Y=in[i].second*sin(in[i].first);
        }
        rep(i,n)for(int j=i+1;j<n;j++){
				if(!rand()%64) continue;
                if(!check(ans+eps,col[i],col[j]))
                    continue;
 
                D low=0,high=ans;
                while(high-low >1e-6+eps){
                    D mid=(low+high)/2.0;
                    if(check(mid,col[i],col[j])) 
                        high=mid;
                    else
                        low=mid;
                }
                ans=(low+high)/2.0;
        }
 		cout.precision(9);
       	cout << fixed << ans << endl;
    }
    return 0;
}

Measured memory_bytes: 1448