Problem: You are given n pairs of integers (a_1, b_1), (a_2, b_2), …, (a_n, b_n). All of the integers in the pairs are distinct and are in the range from 1 to 2 ⋅ n inclusive.

Let's call a sequence of integers x_1, x_2, …, x_{2k} good if either 

  * x_1 < x_2 > x_3 < … < x_{2k-2} > x_{2k-1} < x_{2k}, or 
  * x_1 > x_2 < x_3 > … > x_{2k-2} < x_{2k-1} > x_{2k}. 



You need to choose a subset of distinct indices i_1, i_2, …, i_t and their order in a way that if you write down all numbers from the pairs in a single sequence (the sequence would be a_{i_1}, b_{i_1}, a_{i_2}, b_{i_2}, …, a_{i_t}, b_{i_t}), this sequence is good.

What is the largest subset of indices you can choose? You also need to construct the corresponding index sequence i_1, i_2, …, i_t.

Input

The first line contains single integer n (2 ≤ n ≤ 3 ⋅ 10^5) — the number of pairs.

Each of the next n lines contain two numbers — a_i and b_i (1 ≤ a_i, b_i ≤ 2 ⋅ n) — the elements of the pairs.

It is guaranteed that all integers in the pairs are distinct, that is, every integer from 1 to 2 ⋅ n is mentioned exactly once.

Output

In the first line print a single integer t — the number of pairs in the answer.

Then print t distinct integers i_1, i_2, …, i_t — the indexes of pairs in the corresponding order.

Examples

Input


5
1 7
6 4
2 10
9 8
3 5


Output


3
1 5 3


Input


3
5 4
3 2
6 1


Output


3
3 2 1

Note

The final sequence in the first example is 1 < 7 > 3 < 5 > 2 < 10.

The final sequence in the second example is 6 > 1 < 3 > 2 < 5 > 4.

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.util.Comparator;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        DDirtyDeedsDoneDirtCheap solver = new DDirtyDeedsDoneDirtCheap();
        solver.solve(1, in, out);
        out.close();
    }

    static class DDirtyDeedsDoneDirtCheap {

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();

            List<Pair> asc = new ArrayList<>();
            List<Pair> desc = new ArrayList<>();
            for (int i = 0; i < n; i++) {
                int val1 = in.nextInt();
                int val2 = in.nextInt();
                if (val1 < val2) {
                    asc.add(new Pair(val1, val2, i + 1));
                } else {
                    desc.add(new Pair(val1, val2, i + 1));
                }
            }

            asc.sort(Comparator.comparingInt(a -> -a.sc));
            desc.sort(Comparator.comparingInt(a -> a.sc));

            int szA = Math.min(1, asc.size());
            while (asc.size() > szA && asc.get(szA).fs < asc.get(szA - 1).sc) {
                szA++;
            }
            int szD = Math.min(1, desc.size());
            while (desc.size() > szD && desc.get(szD).fs > desc.get(szD - 1).sc) {
                szD++;
            }
            int sz;
            List<Pair> ans;
            if (szA > szD) {
                sz = szA;
                ans = asc;
            } else {
                sz = szD;
                ans = desc;
            }
            out.println(sz);
            for (int i = 0; i < sz; i++) {
                out.print(ans.get(i).idx);
                out.print(' ');
            }
        }

        class Pair {

            int fs;
            int sc;
            int idx;

            public Pair(int fs, int sc, int idx) {
                this.fs = fs;
                this.sc = sc;
                this.idx = idx;
            }
        }
    }

    static class InputReader {

        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
    }
}