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.*;
import java.util.*;

public class cD {
	void run() {
		int n = in.nextInt();
		ArrayList<Long> inc = new ArrayList<>();
		ArrayList<Long> dec = new ArrayList<>();
		for (int i = 0; i < n; i++) {
			int a = in.nextInt();
			int b = in.nextInt();
			if (a < b) {
				inc.add(n * (long) (2 * n - b) + i);
			} else {
				dec.add(n * (long) (a) + i);
			}
		}
		ArrayList<Long> ans = (inc.size() > dec.size()) ? inc : dec;
		Collections.sort(ans);
		out.println(ans.size());
		for (long x : ans) {
			out.print(x % n + 1);
			out.print(" ");
		}
		out.println();
	}

	static MyScanner in;
	static PrintWriter out;

	public static void main(String[] args) throws IOException {
		boolean stdStreams = true;
		String fileName = cD.class.getSimpleName().replaceFirst("_.*", "").toLowerCase();
		String inputFileName = fileName + ".in";
		String outputFileName = fileName + ".out";
		
		Locale.setDefault(Locale.US);
		BufferedReader br;
		if (stdStreams) {
			br = new BufferedReader(new InputStreamReader(System.in));
			out = new PrintWriter(System.out);
		} else {
			br = new BufferedReader(new FileReader(inputFileName));
			out = new PrintWriter(outputFileName);
		}
		in = new MyScanner(br);
		int tests = 1;//in.nextInt();
		for (int test = 0; test < tests; test++) {
			//out.print("Case #" + (test + 1) + ": ");
			new cD().run();
		}
		br.close();
		out.close();
	}
	
	static class MyScanner {
		BufferedReader br;
		StringTokenizer st;

		MyScanner(BufferedReader br) {
			this.br = br;
		}
		
		void findToken() {
			while (st == null || !st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
		}
		
		String next() {
			findToken();
			return st.nextToken();
		}
		
		int nextInt() {
			return Integer.parseInt(next());
		}
		
		long nextLong() {
			return Long.parseLong(next());
		}
		
		double nextDouble() {
			return Double.parseDouble(next());
		}
	}
}