/* -*- coding: utf-8 -*-
 *
 * 1121.cc:  No.1121 Social Distancing in Cinema - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 250000;
const int DY = 9;
const int DX = 10;

/* typedef */

/* global variables */

int xs[MAX_N], ys[MAX_N];
int cs[DY][DX];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  for (int i = 0; i < n; i++) scanf("%d%d", xs + i, ys + i);

  for (int i = 0; i < n; i++)
    cs[ys[i] % DY][(xs[i] + ((ys[i] / DY) & 1) * DX / 2) % DX]++;

  int maxc = -1, maxy = -1, maxx = -1;
  for (int y = 0; y < DY; y++)
    for (int x = 0; x < DX; x++)
      if (maxc < cs[y][x])
	maxc = cs[y][x], maxy = y, maxx = x;
  
  printf("%d\n", maxc);
  for (int i = 0, cont = 0; i < n; i++)
    if (ys[i] % DY == maxy &&
	(xs[i] + ((ys[i] / DY) & 1) * DX / 2) % DX == maxx) {
      if (cont) putchar(' ');
      printf("%d", i + 1);
      cont = 1;
    }
  putchar('\n');
  return 0;
}