#pragma GCC omptimize("unroll-loops")
#pragma GCC optimize("no-stack-protector")
#include <bits/stdc++.h>
using namespace std;

int n;
int x[1000];
int  y[1000];
vector <double> s;

bool comppp (int a,int b) {
    return (a>b);
 }
int main () {
   #ifdef LOCAL
    freopen("moria.in", "r", stdin);
    freopen("moria.out", "w", stdout);
   #endif
    int m , n;
    cin >> m >> n;
    s.resize(m );
    //cout << m << endl;
    for(int i = 0; i < m; i++) {
        cin >> x[i] >> y[i];
    }
//  cout << x[0] << endl;
//  cout << y[0] << endl;
    for(int i = 0; i < m; i++) {

            s[i] = sqrt(pow(x[i] , 2) + pow(y[i], 2));

        }
    //  for(int i = 0; i < s.size(); i++) cout << s[i] << " ";
    //cout << endl;
    sort(s.begin(), s.end());
    //for(int i = 0; i < s.size(); i++) cout << s[i] << " ";
    //cout << endl;
    //cout << s[n] << endl;
    int l = round(pow(s[n], 2));
    cout << l;
    return 0;
}