B

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test  int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    int n;
    cin>>n;

    vector<vector<int>> a;
    vector<int> b;

    for(int i=0; i<n; i++)
    {
        int c;
        cin>>c;

        b.resize(c);
        for(auto &e: b)
            cin>>e;

        a.pb(b);
    }

    int x;
    cin>>x;

    vector<int> ans;
    int few = 1e9;
    int tmp;

    for(int i=0; i<n; i++)
    {
        int f = 0;

        for(auto e: a[i])
        {
            if(e == x)
            {
                f = 1;
                tmp = a[i].size();
                break;
            }
        }

        if(f)
        {
            if(tmp == few)
                ans.pb(i+1);
            else if(tmp < few)
            {
                ans.clear();
                ans.pb(i+1);
                few = tmp;
            }
        }
    }

    cout<<ans.size()<<"\n";
    for(auto e: ans)
        cout<<e<<" ";
    cout<<"\n";
}