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#include <bits/stdc++.h>
using namespace std;
#define all(v) ((v).begin()), ((v).end())
#define yes cout << "YES" << '\n';
#define no cout << "NO" << '\n';
//#define endl '\n'
typedef long long ll;
const int N=1e5+5;
ll mod=1e9+7;
#define int long long
ll n1;

ll mrg (ll x ,ll y )
{
    return (x^y);
}

struct segment_tree
{
    vector<ll> tree;
    void clear()
    {
        tree.clear();
    }

    void init(ll num, const vector<ll>& a)
    {
        n1 = num;
        tree.assign(4 * n1, 0);
        build(a);
    }

    void build(const vector<ll>& a, int id=0,int ns = 0, int ne = n1-1)
    {
        if(ns==ne){
            tree[id] = a[ns];
            return ;
        }
        int l = 2*id+1;
        int r = l+1;
        int md = ns+(ne-ns)/2;
        build(a,l, ns, md);
        build(a,r, md+1, ne);
        tree[id] = mrg(tree[l],tree[r]);
    }


    ll query(int qs, int qe, int id=0, int ns=0, int ne=n1-1)
    {
        if(ns>qe || qs>ne){
            return 0; ///infnity
        }
        if(qs<=ns && qe>=ne){
            return tree[id];
        }
        int l = 2*id+1;
        int r = l+1;
        int md = ns+(ne-ns)/2;
        ll ndl = query(qs, qe, l, ns, md);
        ll ndr = query(qs, qe,r, md+1,ne);
        return mrg(ndl,ndr );
    }

    void upd(int pos , int val , int id=0, int ns=0,int ne=n1-1)
    {
        if(ns>pos || pos>ne){
            return;
        }
        if(ns==ne){
            tree[id]=val;
            return ;
        }
        int l = 2*id+1;
        int r = l+1;
        int md = ns+(ne-ns)/2;
        upd(pos, val,l, ns, md);
        upd(pos, val, r, md+1, ne);
        tree[id] = mrg(tree[l],tree[r]);
    }
} ;

pair<ll,ll> query(ll i,ll j)
{
    cout << i << ' ' << j << endl;
    cout.flush();
    pair<ll,ll> pq={0,0};
    cin >> pq.first >> pq.second;
    return pq;
}
void solve() {
    //multiset<pair<ll,ll>> ms;

   ll n;
   cin >> n;
   vector<ll> v(n);
   set<int> m[41];
   for (int i=0;i<n;i++)
    {
        cin >> v[i];
        for (int b=0;b<=40;++b)
        {
            if ((1ll<<b)&v[i])
            {
                m[b].insert(i);
            }
        }
    }
   ll xr=0;

   pair<ll,ll> q={0,0};
   segment_tree st;

   st.init(n,v);
   xr=st.query(0,n-1);
   if (xr==0)
   {
       q=query(0,0);
   } else {
       ll bit = log2(xr);
       auto it = m[bit].end();
       --it;
       ll id = *it;
       ll ele = v[id];
       for (int b = 0; b <= 40; ++b)
       {
           if ((1ll<<b) & v[id])
           {
               m[b].erase(id);
           }
       }
       xr = st.query(0, id-1) ^ st.query(id+1, n-1);
       st.upd(id, xr);
       v[id] = xr;

       if (xr != 0)
       {
           for (int b = 0; b <= 40; ++b)
           {
               if ((1ll<<b) & xr)
               {
                   m[b].insert(id);
               }
           }
       }
       q = query(id+1, ele-xr);
   }

   while(1)
   {
       if (q.first == 0 && q.second == 0)
       {
           return;
       }
       ll id = q.first-1;
       ll removed = q.second;
       ll e = v[id];
       for (int b = 0; b <= 40; ++b)
       {
           if ((1ll<<b) & e)
           {
               m[b].erase(id);
           }
       }

       v[id] -= removed;
       st.upd(id, v[id]);

       if (v[id] > 0)
       {
           for (int b = 0; b <= 40; ++b)
           {
               if ((1ll<<b) & v[id])
               {
                   m[b].insert(id);
               }
           }
       }

       xr = st.query(0, n-1);
       ll bit = log2(xr);
       auto it = m[bit].end();
       --it;
       id = *it;
       ll ele = v[id];
       for (int b = 0; b <= 40; ++b)
       {
           if ((1ll<<b) & v[id])
           {
               m[b].erase(id);
           }
       }
       xr = st.query(0, id-1) ^ st.query(id+1, n-1);
       st.upd(id, xr);
       v[id] = xr;

       if (xr != 0)
       {
           for (int b = 0; b <= 40; ++b)
           {
               if ((1ll<<b) & xr)
               {
                   m[b].insert(id);
               }
           }
       }
       q = query(id+1, ele-xr);
   }
}


signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    //cout << setprecision(10) << fixed;
    int testcases = 1;
     cin >> testcases;
    while (testcases--) {
        solve();
    }
    return 0;
}