D

#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()
{
    _test
    {
        int n;
        cin>>n;

        vector<int> a(n), b(n);
        for(auto &e: a)  cin>>e;
        for(auto &e: b)  cin>>e;

        vector<int> c;

        for(int i=0; i<n; i++)
            c.pb(a[i] - b[i]);

        vector<int> ans;
        int x = *max_element(c.begin(), c.end());

        for(int i=0; i<n; i++)
        {
            if(x == c[i])
                ans.pb(i+1);
        }

        cout<<ans.size()<<"\n";

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