void output(int path[],pos)

{

    if(pos==) return ;

    output(path,path[pos]);

    printf("%d\n",mice[pos].id);

}

#include <cstdio>

#include <stdlib.h>

#include <algorithm>

#define INF 0x3f3f3f3f

using namespace std;

int n;///n只老鼠

int Count[]= {}; ///count[i]表示构造到第i个老鼠时，序列的最大长度

int path[]= {}; ///path[i]表示构造到第i个老鼠时的前一个老鼠(前驱)

struct mouse

{

    int weight;

    int speed;

    int id;

} mice[];

int cmp(const void *a,const void *b)

{

    struct mouse *p1=(mouse *)a;

    struct mouse *p2=(mouse *)b;

    if(p1->weight==p2->weight)

    {

        if(p1->speed>p2->speed)

            return p2->speed-p1->speed;

        else return p1->speed-p2->speed;

    }

    else return p1->weight-p2->weight;

}

void output(int path[],int pos)

{

    if(pos==) return ;

    output(path,path[pos]);

    printf("%d\n",mice[pos].id);

}

int main()

{

    n=;

    int i=,j=;

    while(scanf("%d%d",&mice[++i].weight,&mice[++j].speed)!=EOF)

    {

        n++;

        mice[n].id=n;

    }

    qsort(mice+,n,sizeof(mice[]),cmp);

    Count[]=;

    for(int i=; i<=n; i++)

    {

        for(int j=; j<i; j++)

        {

            if(mice[i].weight>mice[j].weight&&mice[i].speed<mice[j].speed)

            {

                if(Count[i]<Count[j])

                {

                    Count[i]=Count[j];

                    path[i]=j;

                }

            }

        }

        Count[i]++;

    }

    int _max=;

    int pos;

    for(int i=; i<=n; i++)

    {

        if(Count[i]>_max)

        {

            _max=Count[i];

            pos=i;

        }

    }

    printf("%d\n",_max);

    output(path,pos);

}