#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<stdlib.h>
#include<queue>
#include<stack>
#include<algorithm>
#define LL __int64
using namespace std;
const int MAXN=10000+50;
const int INF=0x3f3f3f3f;
const double EPS=1e-9;
int dir4[][2]={{0,1},{1,0},{0,-1},{-1,0}};
int dir8[][2]={{0,1},{1,1},{1,0},{1,-1},{0,-1},{-1,-1},{-1,0},{-1,1}};
int dir_8[][2]={{-2,1},{-1,2},{1,2},{2,1},{2,-1},{1,-2},{-1,-2},{-2,-1}};
struct node
{
    int w;
    int s;
    int index;
    bool operator<(const node A)const
    {
        if(w!=A.w) return w<A.w;
        return s>A.s;
    }
}a[MAXN];
int dp[MAXN],pre[MAXN];
void print(int p)
{
    if(pre[p]!=-1) print(pre[p]);
    printf("%d\n",a[p].index);
}
int main()
{
    int weight,speed,cnt=0;
    while(scanf("%d %d",&weight,&speed)!=EOF)
    {
        a[cnt].w=weight;
        a[cnt].s=speed;
        a[cnt].index=cnt+1;
        cnt++;
    }
    sort(a,a+cnt);
    memset(dp,0,sizeof(dp));
    memset(pre,-1,sizeof(pre));

    dp[0]=1;
    int id,maxn=-INF;
    for(int i=1;i<cnt;i++)
    {
        dp[i]=1;
        for(int j=0;j<i;j++)
        {
            if(a[i].w!=a[j].w && a[i].s<a[j].s)
            {
                if(dp[j]+1>dp[i])
                {
                    dp[i]=dp[j]+1;
                    pre[i]=j;
                }
            }
        }
        if(dp[i]>maxn)
        {
            maxn=dp[i];
            id=i;
        }
    }
    printf("%d\n",dp[id]);
    print(id);
    return 0;
}