#include<bits/stdc++.h>
#define int long long
using namespace std;
const int M = 1e5 + 5;
const double eps = 1e-7;
int n, k;
struct P {
    int x, y;
}a[M];

struct BIT {
    int s[M];
    inline void clear(int n = 1e5 + 5) {
        memset(s, 0,sizeof(int) * n);
    }
    #define lowbit(x) (x & -x)
    inline void add(int pos, int x) {
        for (; pos <= n; pos += lowbit(pos)) s[pos] = max(s[pos], x);
    }
    inline int ask(int pos) {
        int ans = -1;
        for (; pos; pos -= lowbit(pos)) ans = max(ans, s[pos]);
        return ans;
    }
    #undef lowbit
}ss;

inline bool check(long double mid) {
    vector<long double>v;
    vector<int>val;
    for (int i = 1; i <= n; i++) {
        v.push_back(a[i].y - a[i].x * mid);
    }   
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    ss.clear(n + 5);
    int mx = 1;
    for (int i = 1; i <= n; i++) {
        int pos = lower_bound(v.begin(), v.end(), a[i].y - a[i].x * mid - eps) - v.begin() + 1;
        int now = ss.ask(pos) + 1;
        // cout << pos << " " << now << endl;
        ss.add(pos, now);
        mx = max(mx, now);
    }
    return mx >= k;
}


signed main() {
    ios::sync_with_stdio(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++) {
        cin >> a[i].x >> a[i].y;
    }
    long double l = -1e9, r = 1e9, mid, ans = -114514;
    for (int t = 1; t <= 100; t++){
        mid = (l + r) / 2;
        if (check(mid)) ans = mid, l = mid;
        else r = mid;
    }
    cout << ans << endl;
    return 0;
}