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#include <bits/stdc++.h>
namespace IO {
inline char read() {
static const int IN_LEN = 1000000;
static char buf[IN_LEN], *s, *t;
s == t ? t = (s = buf) + fread(buf, 1, IN_LEN, stdin) : 0;
return s == t ? -1 : *s++;
}
template<class T>
inline void read(T &x) {
static char c;
static bool iosig;
for (c = read(), iosig = false; !isdigit(c); c = read()) {
if (c == -1) return;
c == '-' ? iosig = true : 0;
}
for (x = 0; isdigit(c); c = read())
x = (x + (x << 2) << 1) + (c ^ '0');
iosig ? x = -x : 0;
}
const int OUT_LEN = 1000000;
char obuf[OUT_LEN], *oh = obuf;
inline void print(char c) {
oh == obuf + OUT_LEN ? (fwrite(obuf, 1, OUT_LEN, stdout), oh = obuf) : 0;
*oh++ = c;
}
template<class T>
inline void print(T x) {
static int buf[30], cnt;
if (x == 0) {
print('0');
} else {
x < 0 ? (print('-'), x = -x) : 0;
for (cnt = 0; x; x /= 10) buf[++cnt] = x % 10 | 48;
while (cnt) print((char)buf[cnt--]);
}
}
inline void flush() {
fwrite(obuf, 1, oh - obuf, stdout);
}
}
static const int MAXN = 100010;
static struct Point {
int x, y;
Point(int x = 0, int y = 0) : x(x), y(y) {}
} p[MAXN];
bool flag;
#define long long long
template<typename T>
static inline T square(const T &x) {
return x * x;
}
static inline bool cmp(const Point &p1, const Point &p2) {
return flag ? (p1.y < p2.y || (p1.y == p2.y && p1.x < p2.x)) :
(p1.x < p2.x || (p1.x == p2.x && p1.y < p2.y));
}
static inline bool getSplit(int l, int r) {
register double vx = 0, vy = 0;
register double ax = 0, ay = 0;
for (register int i = l; i <= r; i++) ax += p[i].x, ay += p[i].y;
ax /= r - l + 1, ay /= r - l + 1;
for (register int i = l; i <= r; i++)
vx += square(p[i].x - ax), vy += square(p[i].y - ay);
return vx < vy;
}
class PriorityQueue :
public std::priority_queue<long,
std::vector<long>, std::greater<long> > {
public:
inline void resize(const int n) {
c.resize(n);
}
} a;
PriorityQueue q;
struct Node {
Node *c[2];
int kind;
Point p, r1, r2;
Node(int kind = 0) : kind(0), c() {}
Node(int kind, const Point &p) : kind(kind), p(p), r1(p), r2(p), c() {}
inline void *operator new(size_t) {
static Node pool[MAXN], *cur = pool;
return cur++;
}
inline void maintain() {
if (c[0]) {
r1.x = std::min(c[0]->r1.x, r1.x);
r1.y = std::min(c[0]->r1.y, r1.y);
r2.x = std::max(c[0]->r2.x, r2.x);
r2.y = std::max(c[0]->r2.y, r2.y);
}
if (c[1]) {
r1.x = std::min(c[1]->r1.x, r1.x);
r1.y = std::min(c[1]->r1.y, r1.y);
r2.x = std::max(c[1]->r2.x, r2.x);
r2.y = std::max(c[1]->r2.y, r2.y);
}
}
inline long heuristic(const Point &p) {
return std::max(square<long>(r1.x - p.x), square<long>(r2.x - p.x)) +
std::max(square<long>(r1.y - p.y), square<long>(r2.y - p.y));
}
} *root;
inline Node *build(int l, int r) {
if (l > r) return NULL;
register int mid = l + r >> 1;
flag = getSplit(l, r), std::nth_element(p + l, p + mid, p + r + 1, cmp);
Node *o = new Node(flag, p[mid]);
o->c[0] = build(l, mid - 1), o->c[1] = build(mid + 1, r);
return o->maintain(), o;
}
inline long dis(const Point &a, const Point &b) {
return square<long>(a.x - b.x) + square<long>(a.y - b.y);
}
int cur;
inline void query(Node *o) {
register long d = dis(o->p, p[cur]);
if (d > q.top()) q.pop(), q.push(d);
register long l = (o->c[0] ? o->c[0]->heuristic(p[cur]) : 0);
register long r = (o->c[1] ? o->c[1]->heuristic(p[cur]) : 0);
if (l > r) {
if (o->c[0] && l > q.top()) query(o->c[0]);
if (o->c[1] && r > q.top()) query(o->c[1]);
} else {
if (o->c[1] && r > q.top()) query(o->c[1]);
if (o->c[0] && l > q.top()) query(o->c[0]);
}
}
inline void query(const int pos) {
cur = pos, query(root);
}
#undef long
int main() {
using namespace IO;
register int n, k;
read(n), read(k);
for (register int i = 1; i <= n; i++)
read(p[i].x), read(p[i].y);
root = build(1, n);
q.resize(k * 2);
for (register int i = 1; i <= n; i++) query(i);
print(q.top());
flush();
return 0;
}
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