#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2")
#define watch(x) cout<<(#x)<<"="<<(x)<<'\n'
#define mset(d,val) memset(d,val,sizeof(d))
#define cbug if(DEBUG) cout
#define setp(x) cout<<fixed<<setprecision(x)
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define forn(i,a,b) for(int i=(a);i<(b);i++)
#define fore(i,a,b) for(int i=(a);i<=(b);i++)
#define pb push_back
#define F first
#define S second
#define fbo find_by_order
#define ook order_of_key
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef vector<ii> vii;
//template<typename T>
//using pbds = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
void SD(int t=0){ cout<<"PASSED "<<t<<endl; }
ostream& operator<<(ostream &out, ii x){ out<<"("<<x.F<<","<<x.S<<")"; return out; }
template<typename T> void amax(T &a, T b){ a=max(a,b); }
template<typename T> void amin(T &a, T b){ a=min(a,b); }
struct Hash {
	static uint64_t splitmix64(uint64_t x) {
		// http://xorshift.di.unimi.it/splitmix64.c
		x += 0x9e3779b97f4a7c15;
		x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
		x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
		return x ^ (x >> 31);
	}
	size_t operator()(uint64_t x) const {
		static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
		return splitmix64(x + FIXED_RANDOM);
	}
};

const ll INF = ll(1e18);
const int MOD = 998244353;
const bool DEBUG = 0;
const int MAXN = 100005;
const int LG = 21;

class PointSegmentTree{
private:
	int size_;
	vector<ll> v;
	void update(int p, ll val, int k, int l, int r)
	{
		if(p < l || r < p) return;
		if(l == r){
			v[k]=val;	//modification
			return;
		}
		int mid = (l+r)>>1;
		update(p, val, k*2, l, mid);
		update(p, val, k*2+1, mid+1, r);
		v[k] = merge(v[k*2], v[k*2+1]);
	}
	ll query(int s, int e, int k, int l, int r)
	{
		if(e < l || r < s) return 0; //dummy value
		if(s <= l && r <= e) return v[k];
		int mid = (l+r)>>1;
		ll lc = query(s, e, k*2, l, mid);
		ll rc = query(s, e, k*2+1, mid+1, r);
		return merge(lc, rc);
	}

public:
	PointSegmentTree(): v(vector<ll>()) {}
	PointSegmentTree(int n){
		for(size_=1;size_<n;) size_<<=1;
		v.resize(size_*4);
	}
	//void reset(){}
	inline ll merge(ll x, ll y){
		return max(x, y);
	}
	inline void update(int p, ll val){
		update(p, val, 1, 0, size_-1);
	}
	inline ll query(int l, int r){
		return query(l, r, 1, 0, size_-1);
	}
};

int n,K;
ll x[MAXN], y[MAXN];

bool solve(ld m)
{
	ld sl[n]{};
	forn(i,0,n) sl[i] = y[i] - m * x[i];
	sort(sl, sl + n);

	PointSegmentTree st(n);
	int ans = 0;
	forn(i,0,n)
	{
		int slp = lower_bound(sl, sl + n, y[i] - m * x[i], [](ld a, ld b){ return b - a >= 1e-9; }) - sl;
		int q = st.query(0, slp) + 1;
		st.update(slp, q);
		ans = max(ans, q);
	}
	return ans >= K;
}

int main()
{
	cin.tie(0)->sync_with_stdio(0);

	cin>>n>>K;
	forn(i, 0, n) cin >> x[i] >> y[i];
	int bcnt = 0;
	ld ans = 0;
	for (ld L = -1e10L, R = 1e10L; bcnt < 100; bcnt++)
	{
		ld m = (L + R) / 2;
		if (solve(m))
		{
			ans = m;
			L = m;
		}
		else R = m;
	}
	setp(12);
	cout << ans << '\n';

	return 0;
}