#include<bits/stdc++.h>
using namespace std; 
constexpr int N = 200010;

int sz[N], del[N], n, Sz, cen;
vector<int> vec[N];
vector<pair<int, int>> vec1;

// int V;

void dfs1(int x, int fa) {
    // printf("#%d\n", x);
    sz[x] = 1;
    bool f = true;
    for (auto i:vec[x])
        if (i != fa && !del[i]) {
            dfs1(i, x);
            sz[x] += sz[i];
            if (sz[i]*2 > Sz)
                f = false;
        }
    // printf("end #%d: %d %d", x, f, sz[x]);
    if (f && sz[x]*2 >= Sz)
        cen = x;
}

void dfs2(int x,int fa) {
    sz[x] = 1;
    for (auto i:vec[x])
        if (i != fa && !del[i]) {
            dfs2(i, x);
            sz[x] += sz[i];
        }
}

void solve() {
    dfs1(1, 0);
    while (true) {
        vec1 = {};
        int f;
        dfs2(cen,0);
        // printf("centre=%d\n", cen);
        for (auto i:vec[cen])
            if (!del[i])
                vec1.push_back({sz[i], i});
        if (vec1.size() == 0) {
            printf("! %d\n",cen);
            fflush(stdout);
            return;
        }
        else if (vec1.size() == 1) {
            printf("? %d %d\n", cen, vec1[0].second);
            fflush(stdout);
            scanf("%d",&f);
            printf("! %d\n",f?vec1[0].second:cen);
            fflush(stdout);
            return;
        }
        sort(vec1.begin(),vec1.end());
        int u = vec1[vec1.size()-1].second, v = vec1[vec1.size()-2].second;
        printf("? %d %d\n", u, v);
        fflush(stdout);
        scanf("%d", &f);
        if (f == 0) {
            del[cen] = 1;
            Sz = sz[u];
            dfs1(u, 0);
        }
        else if (f == 1) {
            del[u] = del[v] = 1;
            Sz -= sz[u] + sz[v];
            dfs1(cen, 0);
        }
        else {
            del[cen] = 1;
            Sz = sz[v];
            dfs1(v, 0);
        }
    }
}

int main() {
    int T, x, y;
    scanf("%d", &T);
    while (T--) {
        scanf("%d", &n), Sz = n;
        for (int i = 1;i <= n;++i) vec[i].clear(), del[i] = 0;
        for (int i = 1;i <= n;++i) {
            scanf("%d%d", &x, &y);
            if (x) vec[i].push_back(x), vec[x].push_back(i);
            if (y) vec[i].push_back(y), vec[y].push_back(i);
        }


        solve();
    }
    return 0;
}