hdu1160

import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Stack;

import javax.jws.soap.SOAPBinding.Use;

public class Main
{
	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);
		LinkedList<ok> list=new LinkedList<ok>();
		int nb=1;
		while (sc.hasNext())
		{
			String x=sc.nextLine();
			if (x.equals("")==true)
			{
				break;
			}
			String y[]=x.split(" ");
			list.add(new ok(Integer.valueOf(y[0]), Integer.valueOf(y[1]), nb) );nb++;
		
		}
		Collections.sort(list);
		int dp[]=new int[list.size()];
		int pre[]=new int[list.size()];
		for (int i = 0; i < pre.length; i++)
		{
			dp[i]=1;	pre[i]=-1;
		}
		for (int i = 0; i < list.size(); i++)
		{
			for (int j = 0; j <i; j++)
			{
				if ( list.get(j).a<list.get(i).a && list.get(j).b>list.get(i).b )
				{
					if (dp[i]<dp[j]+1)
					{
						dp[i]=dp[j]+1;pre[i]=j;
					}
				}
			}
		}
		//
		int ddp =-1;int schu=0;
		for (int i = 0; i < pre.length; i++)
		{
			if (ddp<dp[i])
			{
				ddp=dp[i];schu=i;
			}
		}

		Stack<Integer> stack=new Stack<Integer>();
		while(schu!=-1) {
		stack.add(list.get(schu).id);schu=pre[schu];
		}
		System.out.println(stack.size());
		while(!stack.isEmpty()) {
			System.out.println(stack.pop());
		}
	}
}
class ok implements Comparable<ok>{
	int a,b,id;public ok(int a,int b,int c){this.a=a;this.b=b;id=c;}
	@Override
	public int compareTo(ok o)
	{

			return o.b-b;

	}
}
class node{
	int node,max;public node(int node,int max){this.node=node;this.max=max;}
}