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.util.Arrays;
import java.util.Comparator;
import java.util.Scanner; 
import java.util.StringTokenizer; 
  
public class Main 
{ 
    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; 
        } 
    } 
  
    public static void main(String[] args) 
    { 
        FastReader s=new FastReader(); 
        int n=s.nextInt();
        int a[]=new int[n];
        int b[]=new int[n];
        int count=0;
        for(int i=0;i<a.length;i++) {
        	a[i]=s.nextInt();
        	b[i]=s.nextInt();
        	if(a[i]<b[i]) {
        		count++;
        	}
        }
        int iarr[][]=new int[count][3];
        int darr[][]=new int[n-count][3];
        int j=0;
        int k=0;
        for(int i=0;i<a.length;i++) {
        	if(a[i]<b[i]) {
        		iarr[j][0]=a[i];
        		iarr[j][1]=b[i];
        		iarr[j][2]=i;
        		j++;
        	}else {
        		darr[k][0]=a[i];
        		darr[k][1]=b[i];
        		darr[k][2]=i;
        		k++;
        	}
        }
        
        Arrays.sort(iarr,new Comparator<int[]>() {
        	@Override
        	public int compare(int a1[],int a2[]) {
        		return a2[1]-a1[1];
        	}
        });
        
        Arrays.sort(darr,new Comparator<int[]>() {
        	@Override
        	public int compare(int a1[],int a2[]) {
        		return a1[1]-a2[1];
        	}
        });
//        for(int i=0;i<iarr.length;i++) {
//        	for(int jj=0;jj<3;jj++)
//        		System.out.print(iarr[i][jj]+" ");
//        	System.out.println();
//        }
//        for(int i=0;i<darr.length;i++) {
//        	for(int jj=0;jj<3;jj++)
//        		System.out.print(darr[i][jj]+" ");
//        	System.out.println();
//        }
        if(iarr.length>darr.length) {
        	System.out.println(iarr.length);
        	for(int i=0;i<iarr.length;i++) 
        		System.out.print(iarr[i][2]+1+" ");
            	System.out.println();
            
        }else {
        	System.out.println(darr.length);
        	for(int i=0;i<darr.length;i++) 
        		System.out.print(darr[i][2]+1+" ");
            	System.out.println();
            
        }

              
    }
    
}