#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5+10;
int T,n,vis[N];
vector<int> e[N];

void link(int x,int y){e[x].push_back(y); e[y].push_back(x);}

int dep[N],x,y,dx[N],dy[N];
void dfs(int u,int fa){
    if(!vis[u])return;
    for(auto v : e[u])if(v != fa){
        dep[v] = dep[u] + 1;
        dfs(v,u);
    }
}

void solve(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++)e[i].clear(),vis[i] = 1;
    for(int i=1;i<=n;i++){
        int x,y; scanf("%d%d",&x,&y);
        if(x)link(i,x); if(y)link(i,y);
    }
    while(1){
        int cnt = 0,ans = 0;
        for(int i=1;i<=n;i++)if(vis[i])cnt++,ans = i;
        if(cnt == 1){
            printf("! %d\n",ans); fflush(stdout);
            return;
        }
        x = y = 0;
        dep[ans] = 0; dfs(ans,0);
        for(int i=1;i<=n;i++)if(vis[i] && dep[i] > dep[x])x = i;
        dep[x] = 0; dfs(x,0); 
        for(int i=1;i<=n;i++)if(vis[i] && dep[i] > dep[y])y = i;
        for(int i=1;i<=n;i++)dx[i] = dep[i];

        dep[y] = 0; dfs(y,0); 
        for(int i=1;i<=n;i++)dy[i] = dep[i];
        //
        printf("? %d %d\n",x,y); fflush(stdout);
        int res; scanf("%d",&res);
        for(int i=1;i<=n;i++)if(vis[i]){
            if(res == 0)vis[i] = dx[i] < dy[i];
            else if(res == 1)vis[i] = dx[i] == dy[i];
            else vis[i] = dx[i] > dy[i];
        }
    }
}

int main(){
    scanf("%d",&T);
    while(T--)solve();

    return 0;
}