#include <bits/stdc++.h>
using namespace std;
using db = long double;
using ll = long long;

const int N = 2e5 + 50;
using pll = pair<ll, ll>;
const db eps = 1e-15;

int n, k;
pll p[N];
db w[N];

bool check(db mid)
{
    for (int i = 1; i <= n; i++)
        w[i] = (p[i].second - mid * p[i].first) + (i * eps);

    set<long double> s;
    for (int i = 1; i <= n; i++)
    {
        auto x = w[i];
        if (!s.empty() && x < *s.rbegin())
            s.erase(s.lower_bound(x));
        s.insert(x);
    }
    return s.size() >= k;
}

int main()
{
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> p[i].first >> p[i].second;

    db l = -3e9, r = 3e9;
    for (int cnt = 1; cnt <= 60; cnt++)
    {
        db mid = l + (r - l) / 2;
        if (check(mid))
        {
            l = mid;
        }
        else
            r = mid;
    }
    cout << fixed << setprecision(15) << l << "\n";
    return 0;
}