#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
const double EPS = 1e-10;
const double PI = acos(-1);
class EDividePoints {
 public:
  int N;
  void rec(std::ostream& out, vector<pair<int, int>>& vec) {
    vector<vector<int>> par(2);
    for (int i = (0); i < (N); ++i)
      par[((vec[i].first + vec[i].second) % 2 + 2) % 2].push_back(i + 1);
    if (not par[0].empty() and (int)(par[0]).size() < N) {
      out << (int)(par[0]).size() << '\n';
      for (auto u : par[0]) out << u << ' ';
      out << '\n';
      return;
    }
    vector<vector<vector<int>>> ids(2, vector<vector<int>>(2));
    for (int i = (0); i < (N); ++i) {
      ids[(vec[i].first % 2 + 2) % 2][(vec[i].second % 2 + 2) % 2].push_back(i +
                                                                             1);
    }
    for (int i = (0); i < (2); ++i)
      for (int j = (0); j < (2); ++j)
        if (not ids[i][j].empty() and (int)(ids[i][j]).size() < N) {
          out << (int)(ids[i][j]).size() << '\n';
          for (auto u : ids[i][j]) out << u << ' ';
          out << '\n';
          return;
        }
    for (int i = (0); i < (N); ++i) {
      if (vec[i].first % 2) vec[i].first--;
      if (vec[i].second % 2) vec[i].second--;
      vec[i].first /= 2, vec[i].second /= 2;
    }
    rec(out, vec);
  }
  void solve(std::istream& in, std::ostream& out) {
    ios_base::sync_with_stdio(false);
    in.tie(nullptr), out.tie(nullptr);
    in >> N;
    vector<pair<int, int>> A(N);
    for (int i = (0); i < (N); ++i) in >> A[i].first >> A[i].second;
    rec(out, A);
  }
};
int main() {
  EDividePoints solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
