1 #include <cstdio>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <iostream>
 5 #include <vector>
 6 #include <queue>
 7 using namespace std;
 8 
 9 #define N 1000005
10 
11 int from[N], l[65], r[65];
12 bool visited[N];
13 int n;
14 vector<int>ve[65];
15 
16 int march(int u){
17     int v, i;
18     for(i=0;i<ve[u].size();i++){
19         v=ve[u][i];
20         if(!visited[v]){
21             visited[v]=true;
22             if(from[v]==-1||march(from[v])){
23             from[v]=u;
24             return 1;
25            }
26         }
27     }
28     return 0;
29 }
30 
31 main()
32 {
33     int t, i, j, k, x, y;
34     cin>>t;
35     while(t--){
36         scanf("%d",&n);
37         for(i=1;i<=n;i++){
38             scanf("%d %d",&l[i],&r[i]);
39         }
40         for(i=1;i<=n;i++) ve[i].clear();
41         for(i=1;i<=n;i++){
42             for(j=l[i];j<=r[i];j++){
43                 ve[i].push_back(j);
44             }
45         }
46         int num=0;
47         int ans[65];
48         k=0;
49         memset(from,-1,sizeof(from));
50         for(i=n;i>=1;i--){
51             memset(visited,false,sizeof(visited));
52             if(march(i)){          //若有增广路径   说明匹配成功 
53                 num++;
54                 ans[k++]=i;
55             }
56         }
57         sort(ans,ans+k);
58         printf("%d\n%d",num,ans[0]);
59         for(i=1;i<k;i++) printf(" %d",ans[i]);
60         cout<<endl;
61     }
62 }