#define pragma

#ifdef pragma
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#endif // pragma

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define all(x) begin(x), end(x)
#define pb push_back
#define x first
#define y second
#define int long long
#define zero(two) memset(two, 0, sizeof(two))

using namespace std;
using namespace __gnu_pbds;


typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pii;
typedef long double ld;
typedef vector<vi> matrix;
template<typename T>
using kawaii_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(10);
    #if _offline
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
}

const int MAXN = 1e5 + 10;
const int INF = 1e18 + 7;
const int MAXLOG = 20;
const int MOD = 998244353;
const int BASE = 47;

struct p {
    int x, y, n;
};

bool cmp(p a, p b) {
    return a.y > b.x && a.y > b.y;
}

bool cmp2(p a, p b) {
    return a.y < b.x && a.y < b.y;
}

signed main() {
    seriy();
    int n;
    cin >> n;
    vector<p> a(n), f, s;
    for(int i = 0; i < n; i++) {
        cin >> a[i].x >> a[i].y;
        if(a[i].x < a[i].y) f.pb({a[i].x, a[i].y, i});
        else s.pb({a[i].x, a[i].y, i});
    }
    vi ans1, ans2;
    sort(all(f), cmp);
    sort(all(s), cmp2);
    int cur = 0;
    while(cur < f.size()) {
        if(cur + 1 == f.size()) {
            ans1.pb(f[cur].n);
            break;
        }
        if(f[cur].y > f[cur + 1].x) ans1.pb(f[cur].n);
        cur++;
    }
    cur = 0;
    while(cur < s.size()) {
        if(cur + 1 == s.size()) {
            ans2.pb(s[cur].n);
            break;
        }
        if(s[cur].y < s[cur + 1].x) ans2.pb(s[cur].n);
        cur++;
    }
    if(ans1.size() < ans2.size()) {
        cout << ans2.size() << '\n';
        for(auto i : ans2) {
            cout << i + 1 << " ";
        }
    }
    else {
        cout << ans1.size() << '\n';
        for(auto i : ans1) {
            cout << i + 1 << " ";
        }
    }
    return 0;
}