#include <stdio.h>

 #include <algorithm>

 #include <string.h>

 #include <stack>

 using namespace std;

 const int N =  + ;

 const int inf = 0x3f3f3f3f;

 struct node

 {

     int a,b,id;

     bool operator < (const node & temp) const

     {

         return a == temp.a ? b > temp.b : a < temp.a;

     }

 }p[N];

 struct state

 {

     int now,pre,len;

 }dp[N];

 int main()

 {

     int n = ;

     int a,b;

     while(scanf("%d%d",&a,&b) == )

     {

         n++;

         p[n] = (node){a,b,n};

         //if(n == 9) break;

     }

     sort(p+,p++n);

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

     {

         int pos = -;

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

         {

             if(!(p[j].a < p[i].a && p[j].b > p[i].b)) continue;

             if(pos == -) pos = j;

             else if(dp[j].len > dp[pos].len) pos = j;

         }

         if(pos == -) dp[i] = (state){i,-,};

         else dp[i] = (state){i,pos,dp[pos].len + };

     }

     int ind = ;

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

     {

         if(dp[i].len > dp[ind].len) ind = i;

     }

     stack<int> S;

     int temp = ind;

     while(ind != -)

     {

         S.push(ind);

         ind = dp[ind].pre;

     }

     printf("%d\n",S.size());

     while(!S.empty())

     {

         int x = S.top(); S.pop();

         printf("%d\n",p[x].id);

     }

     return ;

 }