import std.algorithm, std.array, std.container, std.range, std.bitmanip;
import std.numeric, std.math, std.bigint, std.random, core.bitop;
import std.string, std.regex, std.conv, std.stdio, std.typecons;

auto maxX = 20000, maxY = 20000;

void main()
{
  auto n = readln.chomp.to!size_t;
  auto pi = iota(n)
    .map!(_ => readln.split.map!(to!int))
    .map!(rd => point(rd[0], rd[1])).array;

  auto xb = new int[][](maxX + 1);
  auto yb = new int[][](maxY + 1);

  auto r = 0;
 loop: foreach (int i, p; pi) {
    auto xi = max(p.x - 10, 0), xa = min(p.x + 10, maxX);
    auto yi = max(p.y - 10, 0), ya = min(p.y + 10, maxY);
    int[] xc, yc;
    foreach (x; xi..xa+1) xc ~= xb[x];
    foreach (y; yi..ya+1) yc ~= yb[y];
    foreach (c; setIntersection(xc.sort().uniq(), yc.sort().uniq()))
      if ((p - pi[c]).hypot2 < 400) continue loop;
    xb[xi] ~= i; xb[xa] ~= i;
    yb[yi] ~= i; yb[ya] ~= i;
    ++r;
  }

  writeln(r);
}

struct Point(T) {
  T x, y;

  point opBinary(string op)(point rhs) {
    static if (op == "+") return point(x + rhs.x, y + rhs.y);
    else static if (op == "-") return point(x - rhs.x, y - rhs.y);
  }

  int hypot2() { return x ^^ 2 + y ^^ 2; }
}

alias Point!int point;