package contest200722; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.Comparator; import java.util.InputMismatchException; import java.util.Random; public class C2 { InputStream is; PrintWriter out; String INPUT = ""; void solve() { int n = ni(); int[][] co = new int[n][]; for(int i = 0;i < n;i++){ co[i] = new int[]{ni(), ni(), i}; } for(int K = 0;K < 4;K++){ int[][] seled = go(co); if(seled.length >= (n+89)/90){ int p = seled.length; out.println(p); for(int i = 0;i < p;i++){ out.print(seled[i][2]+1 + " "); } out.println(); return; } for(int[] c : co){ int d = c[0]; c[0] = c[1]; c[1] = -d; } } Random gen = new Random(); while(true){ double[][] xco = new double[n][]; double theta = gen.nextDouble() * Math.PI * 2; double st = Math.sin(theta); double ct = Math.cos(theta); for(int i = 0;i < n;i++){ xco[i] = new double[]{ ct * co[i][0] - st * co[i][1], st * co[i][0] + ct * co[i][1], i }; } double[][] seled = go(xco); if(seled.length >= (n+89)/90){ int p = seled.length; out.println(p); for(int i = 0;i < p;i++){ out.print((int)seled[i][2]+1 + " "); } out.println(); return; } } } int[][] go(int[][] co) { int n = co.length; int[][] seled = new int[n][]; Arrays.sort(co, new Comparator() { public int compare(int[] a, int[] b) { if(a[0] != b[0])return a[0] - b[0]; return a[1] - b[1]; } }); int p = 0; int k = 0; outer: for(int i = 0;i < n;i++){ for(int j = k;j < p;j++){ if(seled[j][0] <= co[i][0] - 10){ k++; continue; } if(d2(co[i], seled[j]) < 100)continue outer; } seled[p++] = co[i]; } return Arrays.copyOf(seled, p); } public static long d2(int[] a, int[] b) { return (long)(b[0]-a[0])*(b[0]-a[0])+(long)(b[1]-a[1])*(b[1]-a[1]); } double[][] go(double[][] co) { int n = co.length; double[][] seled = new double[n][]; Arrays.sort(co, new Comparator() { public int compare(double[] a, double[] b) { return Double.compare(a[0], b[0]); } }); int p = 0; int k = 0; outer: for(int i = 0;i < n;i++){ for(int j = k;j < p;j++){ if(seled[j][0] <= co[i][0] - 10){ k++; continue; } if(d2(co[i], seled[j]) < 100)continue outer; } seled[p++] = co[i]; } return Arrays.copyOf(seled, p); } public static double d2(double[] a, double[] p) { return ((a[0]-p[0])*(a[0]-p[0])+(a[1]-p[1])*(a[1]-p[1])); } void run() throws Exception { // int n = 500, m = 99999; // Random gen = new Random(); // StringBuilder sb = new StringBuilder(); // sb.append(n*n + " "); // for (int i = 0; i < n; i++) { // for(int j = 0;j < n;j++){ // sb.append(i + " " + j + "\n"); // } // } // INPUT = sb.toString(); is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){ // @Override // public void run() { // long s = System.currentTimeMillis(); // solve(); // out.flush(); // if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // } // }; // t.start(); // t.join(); } public static void main(String[] args) throws Exception { new C2().run(); } private byte[] inbuf = new byte[1024]; public int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private long[] nal(int n) { long[] a = new long[n]; for(int i = 0;i < n;i++)a[i] = nl(); return a; } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[][] nmi(int n, int m) { int[][] map = new int[n][]; for(int i = 0;i < n;i++)map[i] = na(m); return map; } private int ni() { return (int)nl(); } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); } }