#include <bits/stdc++.h>
using namespace std;
const int PRIME = 1e9 + 7;
const int INF = 2e9;
const int MAX_N = 1e3 + 6;
long long ans = 0;
int n, m = 0, k, r = 0;
struct parR {
  int a, b, id;
  bool operator<(const parR& p) const {
    if (b != p.b)
      return b > p.b;
    else
      return a > p.a;
  }
};
struct parM {
  int a, b, id;
  bool operator<(const parM& p) const {
    if (b != p.b)
      return b < p.b;
    else
      return a < p.a;
  }
};
vector<parM> tabM;
vector<parR> tabR;
vector<int> resM;
vector<int> resR;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  int ia, ib;
  parM tM;
  parR tR;
  for (int i = (1); i <= (n); ++i) {
    cin >> ia >> ib;
    if (ia < ib) {
      tR.a = ia;
      tR.b = ib;
      tR.id = i;
      tabR.push_back(tR);
      ++r;
    } else {
      tM.a = ia;
      tM.b = ib;
      tM.id = i;
      tabM.push_back(tM);
      ++m;
    }
  }
  sort(tabM.begin(), tabM.end());
  sort(tabR.begin(), tabR.end());
  int prv = INF;
  for (int pos = (0); pos < (r); ++pos) {
    if (prv > tabR[pos].a) {
      prv = tabR[pos].b;
      resR.push_back(tabR[pos].id);
    }
  }
  prv = 0;
  for (int pos = (0); pos < (m); ++pos) {
    if (prv < tabM[pos].a) {
      prv = tabM[pos].b;
      resM.push_back(tabM[pos].id);
    }
  }
  if (resR.size() > resM.size()) {
    cout << resR.size() << "\n";
    for (int v : resR) cout << v << " ";
  } else {
    cout << resM.size() << "\n";
    for (int v : resM) cout << v << " ";
  }
  return 0;
}
