#include<bits/stdc++.h>
#define iosy ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define int long long
using namespace std;
const int N = 3e3+10;
bool vis[N];
int n,g[N][N],e[N][N];

void dfs(int u,int du){
    n=max(n,u);
    for(int i=1;i<=du;i++){
        if(!g[u][i]){
            cout<<"> "<<i<<endl;
            int v,dv;cin>>v>>dv;
            g[u][i]=v;
            e[u][v]=i;
            dfs(v,dv);
        }
    }
    if(!vis[u]){
        vis[u]=1;
        for(int i=1;i<=du;i++){
            if(!vis[g[u][i]]){
                cout<<"> "<<i<<endl;
                int v,dv;cin>>v>>dv;
                dfs(v,dv);
                cout<<"> "<<e[v][u]<<endl;
                int sb,da_sb;cin>>sb>>da_sb;
            }
        }
    }
}

void solve(){
	int x,dx;cin>>x>>dx;
    n=0;
    dfs(x,dx);
    vector<pair<int,int>> ans;
    for(int i=1;i<=n;i++){
        for(int j=i+1;j<=n;j++){
            if(e[i][j])ans.emplace_back(i,j);
        }
    }
    cout<<"!";
    for(int i=0;i<ans.size();i++){
        cout<<" "<<ans[i].first<<" "<<ans[i].second;
    }
    cout<<endl;
    string s;cin>>s;
    for(int i=0;i<=n+5;i++){
        vis[i]=0;
        for(int j=0;j<=n+5;j++){
            g[i][j]=0;
            e[i][j]=0;
        }
    }
}

signed main(){ 
	iosy;int _=1;
	cin>>_;
	while(_--){solve();}
	return 0;
}