#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<functional>
#include<utility>
#include<vector>
#include<queue>
#include<cassert>
using namespace std;
inline int ask(int x,int y){
    printf("? %d %d\n",x,y);
    fflush(stdout);
    int ret;
    scanf("%d",&ret);
    return ret;
}
inline void ans(int x){
    printf("! %d\n",x);
    fflush(stdout);
}
const int N = 2e5 + 11;
int n,Siz,ecnt,head[N],siz[N],mxsiz[N],s;
bool vis[N];
struct yjx{
    int nxt,to;
}e[N << 1];
inline void save(int x,int y){
    e[++ecnt] = (yjx){head[x],y};
    head[x] = ecnt;
}
bool cmp(int x,int y){
    return siz[x] > siz[y];
}
void getSiz(int now,int fa){
    int i,temp;
    siz[now] = 1;
    for(i = head[now];~i;i = e[i].nxt){
        temp = e[i].to;
        if(temp == fa || vis[temp]) continue;
        getSiz(temp,now);
        siz[now] += siz[temp];
    }
}
void dfs(int now,int fa){
    int i,temp;
    mxsiz[now] = 0;
    for(i = head[now];~i;i = e[i].nxt){
        temp = e[i].to;
        if(temp == fa || vis[temp]) continue;
        dfs(temp,now);
        mxsiz[now] = max(mxsiz[now],siz[temp]);
    }
    mxsiz[now] = max(mxsiz[now],Siz - siz[now]);
    if(!s || mxsiz[now] < mxsiz[s]) s = now;
}
void solve(){
    int rt,i;
    rt = 1;
    while(1){
        s = 0;
        getSiz(rt,0);
        Siz = siz[rt];
        dfs(rt,0);
        if(!mxsiz[s]){
            ans(s);
            return;
        }
        vector<int> son;
        for(i = head[s];~i;i = e[i].nxt){
            if(vis[e[i].to]) continue;
            son.push_back(e[i].to);
        }
        sort(son.begin(),son.end(),cmp);
        //printf("%d %d?\n",s,(int)son.size());
        //puts("");
        //for(i = 0;i < (int)son.size();i++) printf("%d ",son[i]);
        //puts("");
        if(son.size() == 1){
            int x = ask(s,son[0]);
            if(x == 0) ans(s);
            if(x == 2) ans(son[0]);
            return;
        }
        if(son.size() == 2){
            int x = ask(son[0],son[1]);
            if(x == 1){
                ans(s);
                return;
            }
            if(x == 0) rt = son[0];
            if(x == 2) rt = son[1];
            vis[s] = 1;
        }
        if(son.size() == 3){
            int x = ask(son[0],son[1]);
            if(x == 0) rt = son[0],vis[s] = 1;
            if(x == 2) rt = son[1],vis[s] = 1;
            if(x == 1) rt = s,vis[son[0]] = vis[son[1]] = 1;
        }
    }
}
int main(){
    int i,j,k,x,y,t;
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        ecnt = -1;
        for(i = 0;i <= n;i++) head[i] = -1,vis[i] = 0;
        for(i = 1;i <= n;i++){
            scanf("%d %d",&x,&y);
            if(x) save(i,x),save(x,i);
            if(y) save(i,y),save(y,i);
        }
        solve();
    }
    return 0;
}