#pragma GCC optimize("Ofast,O3,unroll-loops")

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define ps push
#define in insert
#define f first
#define s second
#define nl cout<<"\n"
#define ca(v) for(auto i:v) cout<<i<<" ";
#define cbit(x) __builtin_popcount(x)
#define gcd(a, b) __gcd(a, b)
#define lcm(a, b) (a*b/gcd(a, b))
const int xm[4] = {-1, 1, 0, 0};
const int ym[4] = {0, 0, -1, 1};
const int MOD = 1e9 + 7;
const int MAXN = 5e5 + 5;
const ll POW = 9973;

int deg[2505];
int par[2505];
vector<int> adj[2505];
int n;


// vector<int> test_g[20];
// int movecnt = 0;

void iterate(int x);
void dfs(int x) {
    // cout<<x<<" ";
    n = max(n, x);
    if(deg[x] > adj[x].size()){
        iterate(x);
        return;
    }
    int pdx;
    for(int i=1; i<=deg[x]; i++){
        if(adj[x][i-1] == par[x]) {
            pdx = i;
            continue;
        }
        if(par[adj[x][i-1]] != x) continue;
        cout<<"> "<<i<<endl;
        // movecnt++;

        int tx, tdx;
        cin>>tx>>tdx;


        // cout<<x<<"->"<<adj[x][i-1]<<endl;

        dfs(adj[x][i-1]);
    }
    if(par[x]) {
        // movecnt++;
        cout<<"> "<<pdx<<endl;
        // cout<<x<<":"<<pdx<<"|"; ca(adj[x]);
        // cout<<endl;
        // cout<<x<<"->"<<adj[x][pdx-1]<<endl;
        int tx, tdx;
        cin>>tx>>tdx;
    }
}
void iterate(int x) {
    // cout<<x<<" ";
    n = max(n, x);
    if(adj[x].size() == deg[x]) {
        dfs(x);
    }
    else {
        cout<<"> "<<adj[x].size() + 1<<endl;
        // movecnt++;
        int tx,tdx;
        cin>>tx>>tdx;

        // tx = test_g[x][adj[x].size()];
        // tdx = test_g[tx].size();


        deg[tx] = tdx;
        adj[x].pb(tx);
        if(adj[tx].size() == 0) par[tx] = x;
        iterate(tx);
    }
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    int t; cin>>t;
    while(t--){

        n = 1;
        int x;
        int dx;

        cin>>x>>dx;

        deg[x] = dx;
        
        iterate(1);


        cout<<"! ";
        for(int i=1; i<=n; i++) {
            for(int j:adj[i]) if(j>i) cout<<i<<" "<<j<<" ";
        }
        cout<<endl;
        string s; cin>>s;
        assert(s[0] == 'C');
        for(int i=1; i<=n; i++) {
            adj[i].clear();
            deg[i] = 0;
            par[i] = 0;
        }
        n = 1;
    }
}