#include using namespace std; typedef long long ll; typedef vector vint; typedef pair pint; typedef vector vpint; #define rep(i,n) for(int i=0;i<(n);i++) #define REP(i,n) for(int i=n-1;i>=(0);i--) #define reps(i,f,n) for(int i=(f);i<(n);i++) #define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++) #define all(v) (v).begin(),(v).end() #define eall(v) unique(all(v), v.end()) #define pb push_back #define mp make_pair #define fi first #define se second #define chmax(a, b) a = (((a)<(b)) ? (b) : (a)) #define chmin(a, b) a = (((a)>(b)) ? (b) : (a)) const int MOD = 1e9 + 7; const int INF = 1e9; const ll INFF = 1e18; int n; int x[100010], y[100010]; set> se[150][150]; int dist(int x, int y){ return x * x + y * y; } int main(void){ cin >> n; rep(i, n) cin >> x[i] >> y[i]; int ans = 0; rep(i, n){ // printf("x %d y %d\n", x[i], y[i]); int cx = x[i] / 150, cy = y[i] / 150; bool flag = true; for(auto u : se[cx][cy]){ int nx = u.fi, ny = u.se; auto d = dist(nx - x[i], ny - y[i]); // printf("%d %d %d \n", nx, ny, d); if(d < 400){ flag = false; break; } } if(flag){ ans++; se[cx][cy].insert(mp(x[i], y[i])); se[max(cx - 1, 0)][cy].insert(mp(x[i], y[i])); se[cx + 1][cy].insert(mp(x[i], y[i])); se[cx][max(cy - 1, 0)].insert(mp(x[i], y[i])); se[cx][cy + 1].insert(mp(x[i], y[i])); se[max(cx - 1, 0)][max(cy - 1, 0)].insert(mp(x[i], y[i])); se[cx + 1][max(cy - 1, 0)].insert(mp(x[i], y[i])); se[max(cx - 1, 0)][cy + 1].insert(mp(x[i], y[i])); se[cx + 1][cy + 1].insert(mp(x[i], y[i])); } } printf("%d\n", ans); return 0; }