#include <bits/stdc++.h>
using namespace std;

const int MAX = 2e6 + 15;
const double INF = 2e9;

int n, k;
double x[MAX], y[MAX];

int getLis(vector<double>& v){
    int n = v.size(), maxLis = 0;
    vector<double> dp(n + 1, INF);

    dp[0] = -INF;

    for(int i = 0; i < n; i++){
        int curLis = upper_bound(dp.begin(), dp.end(), v[i]) - dp.begin();
        dp[curLis] = min(dp[curLis], v[i]);

        maxLis = max(maxLis, curLis);
    }

    return maxLis;
}

int32_t main(void){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> n >> k;

    for(int i = 1; i <= n; i++)
        cin >> x[i] >> y[i];

    double l = -INF, r = INF;

    for(int i = 0; i < 100; i++){
        double m = (l + r) / 2.0;

        vector<double> cur;
        for(int i = 1; i <= n; i++)
            cur.emplace_back(y[i] - m * x[i]);

        if(getLis(cur) >= k) l = m;
        else r = m;
    }

    cout << setprecision(10) << fixed << l << '\n';
}