#include <cstdio>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <climits>
#include <ctime>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <set>
#include <map>
#include <iostream>
#include <deque>
#include <complex>
#include <string>
#include <iomanip>
#include <sstream>
#include <bitset>
#include <valarray>
#include <unordered_map>
#include <iterator>
#include <assert.h>
using namespace std;
typedef long long int ll;
typedef unsigned int uint;
typedef unsigned char uchar;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;

#define REP(i,x) for(int i=0;i<(int)(x);i++)
#define REPS(i,x) for(int i=1;i<=(int)(x);i++)
#define RREP(i,x) for(int i=((int)(x)-1);i>=0;i--)
#define RREPS(i,x) for(int i=((int)(x));i>0;i--)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();i++)
#define RFOR(i,c) for(__typeof((c).rbegin())i=(c).rbegin();i!=(c).rend();i++)
#define ALL(container) (container).begin(), (container).end()
#define RALL(container) (container).rbegin(), (container).rend()
#define SZ(container) ((int)container.size())
#define mp(a,b) make_pair(a, b)
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"["; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"]"; return os;
}
template<class T> ostream& operator<<(ostream &os, const set<T> &t) {
os<<"{"; FOR(it,t) {if(it!=t.begin()) os<<","; os<<*it;} os<<"}"; return os;
}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
template<class S, class T> pair<S,T> operator+(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first+t.first, s.second+t.second);}
template<class S, class T> pair<S,T> operator-(const pair<S,T> &s, const pair<S,T> &t){ return pair<S,T>(s.first-t.first, s.second-t.second);}

namespace geom{
#define X real()
#define Y imag()
#define at(i) ((*this)[i])
#define SELF (*this)
	enum {TRUE = 1, FALSE = 0, BORDER = -1};
	typedef int BOOL;
	typedef double R;
	const R INF = 1e8;
	R EPS = 1e-6;
	const R PI = 3.1415926535897932384626;
	inline int sig(const R &x) { return (abs(x) < EPS ? 0 : x > 0 ? 1 : -1); }
	inline BOOL less(const R &x, const R &y) {return sig(x-y) ? x < y : BORDER;}
	typedef complex<R> P;
	inline R norm(const P &p){return p.X*p.X+p.Y*p.Y;}
	inline R inp(const P& a, const P& b){return (conj(a)*b).X;}
	inline R outp(const P& a, const P& b){return (conj(a)*b).Y;}
	inline P unit(const P& p){return p/abs(p);}
	inline P proj(const P &s, const P &t){return t*inp(s, t)/norm(t);}
	inline int ccw(const P &s, const P &t, const P &p, int adv=0){
		int res = sig(outp(t-s, p-s));
		if(res || !adv) return res;
		if(sig(inp(t-s, p-s)) < 0) return -2;	// p-s-t
		if(sig(inp(s-t, p-t)) < 0) return 2;	// s-t-p
		return 0;								// s-p-t
	}
	
	
	struct L : public vector<P>{	// line
		L(const P &p1, const P &p2){this->push_back(p1);this->push_back(p2);}
		L(){}
		inline P dir()const {return at(1) - at(0);}
		BOOL online(const P &p)const {return !sig(outp(p-at(0), dir()));}
	};
	struct S : public L{	// segment
		S(const P &p1, const P &p2):L(p1, p2){}
		S(){}
		BOOL online(const P &p)const {
			if(!sig(norm(p - at(0))) || !sig(norm(p - at(1)))) return BORDER;
			return !sig(outp(p-at(0), dir())) && inp(p-at(0), dir()) > -EPS && inp(p-at(1), -dir()) > -EPS ? TRUE: FALSE;
			return !sig(abs(at(0)-p) + abs(at(1) - p) - abs(at(0) - at(1)));
		}
	};
	P crosspoint(const L &l, const L &m);
	struct G : public vector<P>{
		G(size_type size=0):vector(size){}
		S edge(int i)const {return S(at(i), at(i+1 == size() ? 0 : i+1));}
	};

	inline BOOL intersect(const S &s, const L &l){
		return (sig(outp(l.dir(), s[0]-l[0])) * sig(outp(l.dir(), s[1]-l[0])) <= 0);
	}
	inline P crosspoint(const L &l, const L &m){
		R A = outp(l.dir(), m.dir()), B = outp(l.dir(), l[1] - m[0]);
		if(!sig(abs(A)) && !sig(abs(B))) return m[0]; // same line
		if(abs(A) < EPS) assert(false);
		return m[0] + B / A * (m[1] - m[0]);
	}
	
	struct Arrangement{
		struct AEdge{
			int u, v, t;
			R cost;
			AEdge(int u=0, int v=0, int t=0, R cost=0)
				:u(u), v(v), t(t), cost(cost){}
		};
		typedef vector<vector<AEdge>> AGraph;
		vector<P> p;
		AGraph g;
		Arrangement(){}
		Arrangement(vector<S> seg){
			int m = seg.size();
			REP(i, m){
				p.push_back(seg[i][0]);
				p.push_back(seg[i][1]);
				REP(j, i) if(sig(outp(seg[i].dir(), seg[j].dir())) && intersect(seg[i], seg[j]) == TRUE)
					p.push_back(crosspoint(seg[i], seg[j]));
			}
			sort(ALL(p)); UNIQUE(p);
			int n=p.size();
			g.resize(n);
			REP(i, m){
				S &s = seg[i];
				vector<pair<R, int>> ps;
				REP(j, n) if(s.online(p[j])) ps.emplace_back(norm(p[j] - s[0]), j);
				sort(ALL(ps));
				REP(j, (int)ps.size()-1){
					const int u=ps[j].second;
					const int v=ps[j+1].second;
					g[u].emplace_back(u, v, 0, abs(p[u] - p[v]));
					g[v].emplace_back(v, u, 0, abs(p[u] - p[v]));
				}
			}
		}
		
		int getIdx(P q){
			auto it = lower_bound(ALL(p), q);
			if(it == p.end() || *it != q) return -1;
			return it - p.begin();
		}
	};

	struct DualGraph{
		struct DEdge{
			int u, v, f, l;
			R a;
			DEdge(int u, int v, R a):u(u),v(v),f(0),l(0){
				while(PI < a) a -= 2*PI;
				while(a < -PI) a += 2*PI;
				this->a = a;
			}
			bool operator==(const DEdge &opp) const{
				return v==opp.v;
			}
			bool operator<(const DEdge &opp) const{
				return a>opp.a;
			}
			bool operator<(const R &opp) const{
				return a>opp;
			}
			friend ostream& operator<<(ostream &os, const DEdge &t) { return os<<"("<<t.u<<","<<t.v<<","<<t.a*180/PI<<")";}
		};
		
		int n;
		vector<P> p;
		vector<vector<DEdge>> g;
		DualGraph(const vector<P> &p):p(p),g(p.size()),n(p.size()){}
		void add_edge(const int s, const int t){
			R a = arg(p[t]-p[s]);
			g[s].emplace_back(s, t, a);
			g[t].emplace_back(t, s, a > 0 ? a-PI : a+PI);
		}
		void add_polygon(int s, G &t, R a){
			auto e = lower_bound(ALL(g[s]), a-EPS);
			if(e == g[s].end()) e = g[s].begin();
			if(e->f) return;
			e->f = 1;
			t.push_back(p[s]);
			add_polygon(e->v, t, e->a > 0 ? e->a-PI : e->a+PI);
		}
		
		G dual(){
			REP(i, n){
				sort(ALL(g[i]));
				UNIQUE(g[i]);
			}
			int s = min_element(ALL(p)) - p.begin();
			G poly;
			add_polygon(s, poly, -PI*(R).5);
			return poly;
		}
	};

#undef SELF
#undef at
}

using namespace geom;

namespace std{
	bool operator<(const P &a, const P &b){return sig(a.X-b.X) ? a.X < b.X : a.Y+EPS < b.Y;}
	bool operator==(const P &a, const P &b){return abs(a-b) < EPS;}
	istream& operator>>(istream &is, P &p){R x,y;is>>x>>y;p=P(x, y);return is;}
}

int n, m, k;
struct MSQ : public G{
	MSQ(){}
	vector<P> p;
	vector<S> s;
	int m, k;
	MSQ(int m, int k):m(m), k(k){
		REP(i, m) p.push_back(polar((R)1, 2*PI*i/m + PI*(R).5));
		REP(i, m) s.emplace_back(p[i], p[(i+k)%m]);
		Arrangement a(s);
		DualGraph dg(a.p);
		REP(i, a.g.size())REP(j, a.g[i].size()){
			int u = a.g[i][j].u;
			int v = a.g[i][j].v;
			if(u < v) dg.add_edge(u, v);
		}
		(G &)(*this) = dg.dual();
		reverse(this->begin(), this->end());
	}
	void copy(R r, P c, MSQ &msq)const {
		msq.resize(size());
		msq.p.resize(p.size());
		msq.s.resize(s.size());
		msq.m = m;
		msq.k = k;
		REP(i, size())   msq[i] = at(i)*r + c;
		REP(i, p.size()) msq.p[i] = p[i]*r + c;
		REP(i, s.size()) msq.s[i] = S(msq.p[i], msq.p[(i+k)%m]);
	}
	S segment(int i)const {
		return s[i];
	}
};
int convex_contains(const MSQ &msq, const P &g, const P &p) {
	const int n = msq.size();
	int a = 0, b = n;
	const P pg = p-g;
	while (a+1 < b) { // invariant: c is in fan g-P[a]-P[b]
		int c = (a + b) / 2;
		if (outp(msq[a]-g, pg) > 0 && outp(msq[c]-g, pg) < 0) b = c;
		else  a = c;
	}
	b %= n;
	if (outp(msq[a] - p, msq[b] - p) < -EPS) return 0;
	return 1;
}
bool check(const MSQ & temp, R r, const vector<P> &vil, int i, int j){
	MSQ msq;
	L l = temp.segment(j);
	P gp = vil[i] - l[0]*r;
	temp.copy(r, gp, msq);
	vector<P> p;
	P b(-INF, -INF), u(+INF, +INF);
	REP(i, n){
		L l2(vil[i], vil[i] + l.dir());
		int f = 0;
		P ll(INF, INF), rr(-INF, -INF);
		REP(j, m){
			const S s = msq.segment(j);
			if(intersect(s, l2)){
				if(sig(outp(s.dir(), l2.dir()))){
					const P q = crosspoint(s, l2) - l2[0];
					p.push_back(q);
					ll = min(ll, q);
					rr = max(rr, q);
				}
				f = 1;
			}
		}
		u = min(rr, u);
		b = max(ll, b);
		if(!f) return false;
	}
	FOR(q, p){
		if(*q < b || u < *q) continue;
//		if(S(b, u).online(*q) == FALSE) continue;
		if([&](){
			REP(i, n) if(!convex_contains(msq, gp, vil[i] + *q)) return 0;
			return 1;
		}()) return true;
	}
	return false;
}

int main(){
	ios::sync_with_stdio(false);
	while(cin >> n >> m >> k, n){
		MSQ temp(m, k);
		vector<P> vil(n);
		REP(i, n) cin >> vil[i];
		R best = 2000;
		REP(i, n)REP(j, m){
			if(!check(temp, best-EPS, vil, i, j)) continue;
			R l=EPS, r = best;
			REP(itr, 40){
				R m = (l+r)*(R).5;
				if(check(temp, m, vil, i, j)) r = m;
				else l = m;
			}
			best = r;
		}
		printf("%.10f\n", (double)best);
	}
	return 0;
}

Measured memory_bytes: 1648