题目链接：点击打开链接

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <string>
#include <cctype>
#include <vector>
#include <cstdio>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#define maxn 1010
#define _ll __int64
#define ll long long
#define INF 0x3f3f3f3f
#define Mod 1000000007
#define pp pair<int,int>
#define ull unsigned long long
using namespace std;
int p,w[maxn],s[maxn],dp[maxn];
bool ma[maxn][maxn];
void build()
{
	memset(ma,0,sizeof(ma));
	for(int i=1;i<p;i++)
	{
		for(int j=i+1;j<p;j++)
		{
			if(w[i]<w[j]&&s[i]>s[j])
				ma[i][j]=1;
			else if(w[j]<w[i]&&s[j]>s[i])
				ma[j][i]=1;
		}
	}
}
int dfs(int x)
{
	int& ans=dp[x];
	if(ans>0) return ans;
	ans=1;
	for(int i=1;i<p;i++)
		if(ma[x][i])ans=max(ans,dfs(i)+1);
	return ans;
}
void output(int x)
{

	printf("%d\n",x);
	for(int i=1;i<p;i++)
		if(ma[x][i]&&dp[x]==dp[i]+1)
		{
			output(i);
			break;
	    }
}
int main()
{
	p=1;
	while(scanf("%d %d",w+p,s+p)!=EOF)++p;
	build();
	memset(dp,-1,sizeof(dp));
	int ans=-INF,indx;
	for(int i=1;i<p;i++)
		if(ans<dfs(i))
	    {
			ans=dp[i];
			indx=i;
	    }
	printf("%d\n",ans);
	output(indx);
    return 0;
}