#include <bits/stdc++.h>
using namespace std;
int n;
vector<pair<pair<int, int>, int> > v1, v2;
bool cstm1(pair<pair<int, int>, int> x, pair<pair<int, int>, int> y) {
  if (x.first.second == y.first.second) {
    x.first.first < y.first.first;
  }
  return x.first.second > y.first.second;
}
bool cstm2(pair<pair<int, int>, int> x, pair<pair<int, int>, int> y) {
  if (x.first.second == y.first.second) {
    x.first.first > y.first.first;
  }
  return x.first.second < y.first.second;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (int i = (int)1; i <= (int)n; i++) {
    int l, r;
    cin >> l >> r;
    if (l < r) {
      v1.push_back({{l, r}, i});
    } else if (l > r) {
      v2.push_back({{l, r}, i});
    }
  }
  vector<int> ans1, ans2;
  int k1 = (int)v1.size(), k2 = (int)v2.size();
  sort(v1.begin(), v1.end(), cstm1);
  sort(v2.begin(), v2.end(), cstm2);
  pair<pair<int, int>, int> last;
  for (int i = (int)0; i <= (int)k1 - 1; i++) {
    if (i == 0) {
      ans1.push_back(v1[i].second);
      last = v1[i];
    } else if (v1[i].first.first < last.first.second) {
      last = v1[i];
      ans1.push_back(v1[i].second);
    }
  }
  for (int i = (int)0; i <= (int)k2 - 1; i++) {
    if (i == 0) {
      ans2.push_back(v2[i].second);
      last = v2[i];
    } else if (v2[i].first.first > last.first.second) {
      last = v2[i];
      ans2.push_back(v2[i].second);
    }
  }
  cout << max((int)ans1.size(), (int)ans2.size()) << "\n";
  if ((int)ans1.size() >= (int)ans2.size()) {
    for (auto e : ans1) cout << e << " ";
  } else {
    for (auto e : ans2) cout << e << " ";
  }
  return 0;
}
