// clang-format off
#include<bits/stdc++.h>
#define pb push_back
#define P make_pair
#define fi first
#define se second
#define bit(s,x) (((s)>>(x))&1)
#define pnp(s) __builtin_popcountll(s)
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
using namespace std;
mt19937 gen(time(0));
typedef long long ll; 
typedef unsigned long long ull; 
typedef pair<int,int> pii; typedef pair<ll,int> pli; typedef pair<ll,ll> pll; typedef pair<int,ll> pil;
inline ll read(){
	ll x=0,f=1,c=getchar();
	while(c<'0'||c>'9')f=(c=='-'?-1:1),c=getchar();
	while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
	return x*f;
}
const int mod=998244353;
inline int fp(int x,ll p=mod-2,int m=mod,int res=1){
	for(;p;p>>=1){if(p&1)res=1ll*res*x%m;x=1ll*x*x%m;}
	return res;
}
inline void plust(int &x,int y){x=x+y>=mod?x+y-mod:x+y;}
const int N=1e4+10;
// clang-format on
vector<pii>G[N];
int d[N],a[N];
int nowpoint;


inline int ask(int i){
	printf("> %d\n",i);
	fflush(stdout);
	int u=read();
	d[u]=read();
	nowpoint = u;
	return u;
}
inline void tour(int u){
	if(a[u]==d[u])return ;
	int i=++a[u];
	int v=ask(i);
	G[u].pb(P(v,i));
	tour(v);
}
bool vis[N];
inline void dfs(int u,int fa){
	tour(u);
	//printf("dfs(%d,%d)\n",u,fa);
	vis[u]=1;
	int idx=-1;
	for(auto tmp:G[u])if(!vis[tmp.fi]){
		ask(tmp.se);
		dfs(tmp.fi,u);
		assert(nowpoint == u);
	}else if(tmp.fi==fa)idx=tmp.se;
	if(fa)ask(idx);
}
vector<int>vec;
inline void solve(){
	int rt=read();d[rt]=read();
	dfs(rt,0);
	int n=0;
	vec.clear();
	while(!G[n+1].empty()){
		++n;
		for(auto tmp:G[n])if(tmp.fi<n)vec.pb(tmp.fi),vec.pb(n);
	}
	printf("! ");
	for(auto x:vec)printf("%d ",x);
	cout<<endl;
	rep(i,1,n)vis[i]=a[i]=d[i]=0,G[i].clear();
	nowpoint=0;
	char s[10];
	scanf("%s",s);
	if(s[0]!='C')exit(0);
}
int main() {
    //freopen("data.in", "r", stdin);
    // freopen(".in","r",stdin);
    // freopen("myans.out","w",stdout);
	int T=read();while(T--)solve();
    return 0;
}