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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.StringTokenizer;

public class Dirty {

	static class FastReader { 
		BufferedReader br; 
		StringTokenizer st; 

		public FastReader() 
		{ 
			br = new BufferedReader(new
					InputStreamReader(System.in)); 
		} 

		String next() 
		{ 
			while (st == null || !st.hasMoreElements()) 
			{ 
				try
				{ 
					st = new StringTokenizer(br.readLine()); 
				} 
				catch (IOException  e) 
				{ 
					e.printStackTrace(); 
				} 
			} 
			return st.nextToken(); 
		} 

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

		long nextLong() 
		{ 
			return Long.parseLong(next()); 
		} 

		double nextDouble() 
		{ 
			return Double.parseDouble(next()); 
		} 

		String nextLine() 
		{ 
			String str = ""; 
			try
			{ 
				str = br.readLine(); 
			} 
			catch (IOException e) 
			{ 
				e.printStackTrace(); 
			} 
			return str; 
		} 
	}
	
	static class Lnode {
		int x;
		int y;
		int ind;
		Lnode(int x, int y, int ind){
			this.x=x;
			this.y=y;
			this.ind=ind;
		}
	}
	
	static class Lcomp implements Comparator<Lnode> {
		public int compare(Lnode l1, Lnode l2) {
			return l2.x-l1.x;
		}
	}
	
	static class Gnode{
		int x;
		int y;
		int ind;
		Gnode(int x, int y, int ind){
			this.x=x;
			this.y=y;
			this.ind=ind;
		}
	}
	
	static class Gcomp implements Comparator<Gnode> {
		public int compare(Gnode g1, Gnode g2) {
			return g1.y-g2.y;
		}
	}

	public static void main(String[] args) {
		
		FastReader sc = new FastReader();
	    OutputStream outputstream = System.out;
	    PrintWriter out = new PrintWriter(outputstream);
	    
	    int n = sc.nextInt();
	    ArrayList<Lnode> less = new ArrayList();
	    ArrayList<Gnode> great = new ArrayList();
	    for(int i = 1; i <= n; i++){
	    	int a = sc.nextInt();
	    	int b = sc.nextInt();
	    	if(a<b) less.add(new Lnode(a,b,i));
	    	else great.add(new Gnode(a,b,i));
	    }
	    Collections.sort(less, new Lcomp());
	    Collections.sort(great, new Gcomp());
	    if(less.size()>great.size()) {
	    	out.println(less.size());
	    	for(Lnode l : less) {
	    		out.print(l.ind + " ");
	    	}
	    	out.println();
	    } else {
	    	out.println(great.size());
	    	for(Gnode g : great) {
	    		out.print(g.ind + " ");
	    	}
	    	out.println();
	    }
	    out.close();
	}

}