#include<iostream>
#include<vector>
#include<cstring>
#include<unordered_map>
using namespace std;
const int MX=2550;

int T;
int start, num, now;
void ask(int e)
{
    cout << "> " << e << '\n';
    cout.flush();
    cin >> now >> num;
}
int main()
{
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    cin >> T;
    while(T--)
    {
        vector<unordered_map<int,int>> G(MX);
        vector<int> fa(MX), id(MX);
        cin >> start >> num; now=start;
        while(now!=start||id[now]!=num)
        {
            if(id[now]==num) {ask(G[now][fa[now]]); continue;} //finish subtree & return to father
            int pre=now;
            ask(++id[now]); //try to expand
            G[pre][now]=id[pre]; //pre's try num
            if(now==fa[pre]) ask(G[now][pre]); //KEY edge, return to son
            else if(!fa[now]) fa[now]=pre; //upd KEY edge
        }
        cout << "! ";
        for(int u=1;u<MX;u++)
            for(auto [v,id]:G[u])
                if(u<v) cout << u << " " << v << " ";
        cout << '\n'; cout.flush();
        string s; cin >> s;
    }
    return (0-0);
}