#include <bits/stdc++.h>
using namespace std;
namespace std {
template <>
struct hash<pair<int, int>> {
  size_t operator()(const pair<int, int> &x) const {
    long long P = 38923, Q = 109797901;
    return (size_t)((x.first * P + x.second) % Q);
  }
};
};  // namespace std
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
void print(T t) {
  cout << t << endl;
}
template <typename T, typename... Args>
void print(T t, Args... args) {
  cout << t << " ";
  print(args...);
}
int n, a, b;
vector<pair<pair<int, int>, int>> g, l, sol;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  for (int i = min((int)0, (int)n); i < max((int)0, (int)n); i += 1) {
    cin >> a >> b;
    if (a < b) {
      l.push_back({{a, b}, i});
    } else if (a > b) {
      g.push_back({{a, b}, i});
    } else {
      l.push_back({{a, b}, i});
      g.push_back({{a, b}, i});
    }
  }
  sort(l.begin(), l.end());
  reverse(l.begin(), l.end());
  sort(g.begin(), g.end());
  if ((int)(l).size() > (int)(g).size())
    sol = l;
  else
    sol = g;
  cout << (int)(sol).size() << "\n";
  for (int i = min((int)0, (int)(int)(sol).size());
       i < max((int)0, (int)(int)(sol).size()); i += 1)
    cout << (sol[i].second + 1) << " \n"[i == (int)(sol).size() - 1];
  return 0;
}
