#include<stdio.h>
#include<stdlib.h>
#include<stdint.h>
#include<inttypes.h>

typedef struct union_find {
  int32_t *parent;
  int32_t size;
} union_find;

void init_union_find (union_find * const u) {
  for (int32_t i = 0; i < u->size; ++i){
    u->parent[i] = -1;
  }
}

union_find* new_union_find (const int32_t size) {
  union_find * const u = (union_find *) calloc (1, sizeof (union_find));
  u->parent = (int32_t *) calloc (size, sizeof (int32_t));
  u->size = size;
  init_union_find (u);
  return u;
}

int32_t root (union_find * const u, int32_t x) {
  if (u->parent[x] < 0) return x;
  return u->parent[x] = root (u, u->parent[x]);
}

int same (union_find * const u, const int32_t x, const int32_t y) {
  return root (u, x) == root (u, y);
}

void unite (union_find * const u, int32_t x, int32_t y) {
  x = root (u, x);
  y = root (u, y);
  if (x == y) return;
  if (u->parent[x] > u->parent[y]) {
    const int32_t swap = x;
    x = y;
    y = swap;
  }
  u->parent[x] += u->parent[y];
  u->parent[y] = x;
}

typedef int32_t i32;
typedef int64_t i64;

#define ALLOC(size,type) ((type*)calloc((size),sizeof(type)))

typedef struct point {
  i32 x, y;
} point;

i64 distance (point a, point b) {
  i64 dx = a.x - b.x;
  i64 dy = a.y - b.y;
  return dx * dx + dy * dy;
}

void run (void) {
  i32 n;
  scanf ("%" SCNi32, &n);
  point *p = ALLOC (n, point);
  for (i32 i = 0; i < n; ++i) {
    scanf ("%" SCNi32 "%" SCNi32, &p[i].x, &p[i].y);
  }
  union_find *u = new_union_find (n);
  i64 l = 0;
  i64 r = 200000000;
  while (r - l > 1) {
    i64 m = (l + r) / 2;
    init_union_find (u);
    i64 f = 100 * m * m;
    for (i32 i = 0; i < n; ++i) {
      for (i32 j = i + 1; j < n; ++j) {
        if (distance (p[i], p[j]) <= f) {
          unite (u, i, j);
        }
      }
    }
    if (same (u, 0, n - 1)) {
      r = m;
    } else {
      l = m;
    }
  }
  i64 ans = r * 10;
  printf ("%" PRIi64 "\n", ans);
}

int main (void) {
  run();
  return 0;
}