#include <bits/stdc++.h>
#define int long long

using namespace std;

constexpr int inf = 1E18;

int ask (int x, int y) {
    cout << "? " << x << " " << y << endl;

    int t;
    cin >> t;

    return t;
}

void Print (int x) {
    cout << "! " << x << endl;
}

void solve () {
    int n;
    cin >> n;

    vector <vector <int>> e (n + 1);
    for (int i = 1; i <= n; i ++) {
        int x, y;
        cin >> x >> y;

        if (x) {
            e[x].push_back (i);
            e[i].push_back (x);
        }
        if (y) {
            e[y].push_back (i);
            e[i].push_back (y);
        }
    }

    vector <bool> ok (n + 1);

    auto work = [&] (auto &&self, int x, int fa) -> void {
        ok[x] = true;
        for (auto y : e[x]) {
            if (y == fa) {
                continue;
            }
            if (ok[y]) {
                continue;
            }
            self (self, y, x);
        }
    };

    while (true) {
        int rt;
        int m = 0;
        for (int i = 1; i <= n; i ++) {
            if (! ok[i]) {
                rt = i;
                m ++;
            }
        }
        int cent;
        vector <int> sz (n + 1, 1);
        vector <int> wt (n + 1);
        auto dfs = [&] (auto &&self, int x, int fa) -> void {
            for (auto y : e[x]) {
                if (y == fa) {
                    continue;
                }
                if (ok[y]) {
                    continue;
                }
                self (self, y, x);
                sz[x] += sz[y];
                wt[x] = max (wt[x], sz[y]);
            }
            wt[x] = max (wt[x], m - sz[x]);
        };
        dfs (dfs, rt, -1);
        for (int i = 1; i <= n; i ++) {
            if (! ok[i] && wt[i] <= m / 2) {
                cent = i;
                break;
            }
        }
        vector <int> b;
        for (auto y : e[cent]) {
            if (! ok[y]) {
                b.push_back (y);
            }
        }
        if (b.size () == 3) {
            int t = ask (b[0], b[1]);
            if (t == 0) {
                work (work, cent, b[0]);
            } else if (t == 1) {
                work (work, b[0], cent);
                work (work, b[1], cent);
            } else {
                work (work, cent, b[1]);
            }
        } else if (b.size () == 2) {
            int t = ask (b[0], b[1]);
            if (t == 0) {
                work (work, cent, b[0]);
            } else if (t == 1) {
                Print (cent);
                return;
            } else {
                work (work, cent, b[1]);
            }
        } else if (b.size () == 1) {
            int t = ask (cent, b[0]);
            if (t == 0) {
                Print (cent);
            } else {
                Print (b[0]);
            }
            return;
        } else {
            Print (cent);
            return;
        }
    }
}

signed main () {
    ios::sync_with_stdio (false);
    cin.tie (nullptr);

    int T = 1;
    cin >> T;

    while (T --) {
        solve ();
    }

    return 0;
}