#include<bits/stdc++.h>

using namespace std;
const int N = 2e5 + 10;
int n, cnt, T;
int lft, rt, minn;
int head[N], pre[N], siz[N];
bool del[N];

struct Edge{
    int to, nxt;
}e[N << 1];

void add(int u, int v) {
    e[++cnt].to = v;
    e[cnt].nxt = head[u];
    head[u] = cnt;
}

void getrt(int now, int fa) {
    siz[now] = 1;
    int maxsiz = 0;
    for(int i = head[now]; i; i = e[i].nxt) {
        int y = e[i].to;
        if(y == fa || del[y]) continue;
        getrt(y, now);
        maxsiz = max(maxsiz, siz[y]);
        siz[now] += siz[y];
    }
    maxsiz = max(maxsiz, lft - siz[now]);
    if(maxsiz < minn) {
        rt = now;
        minn = maxsiz;
    }
    return;
}

void dfs(int now, int fa) {
    siz[now] = 1;
    for(int i = head[now]; i; i = e[i].nxt) {
        int y = e[i].to;
        if(y == fa || del[y]) continue;
        dfs(y, now);
        siz[now] += siz[y];
    }
}

void dele(int now, int fa) {
    if(now == -1) return;
    del[now] = 1; --lft;
    for(int i = head[now]; i; i = e[i].nxt) {
        int y = e[i].to;
        if(y == fa) continue;
        dele(y, now);
    }
}

void solve() {
    scanf("%d", &n);
    cnt = 0; lft = n;
    for(int i = 1; i <= n; ++i) head[i] = del[i] = 0;
    for(int i = 1; i <= n; ++i) {
        int lson, rson;
        scanf("%d%d", &lson, &rson);
        if(lson) {
            add(i, lson); add(lson, i);
        }
        if(rson) {
            add(i, rson); add(rson, i);
        }
    }
    int lgp = 0;
    rt = 1; minn = INT_MAX;
    while(n >> lgp) {
        lgp++;
        minn = INT_MAX;
        for(int i = 1; i <= n; ++i) siz[i] = 0;
        getrt(rt, 0);
        for(int i = 1; i <= n; ++i) siz[i] = 0;
        dfs(rt, 0);
        int fir = -1, sizfir = 0;
        int sec = -1, sizsec = 0;
        int thir = -1;
        for(int i = head[rt]; i; i = e[i].nxt) {
            int y = e[i].to;
            if(del[y]) continue;
            if(siz[y] >= sizfir) {
                sec = fir; sizsec = sizfir;
                fir = y; sizfir = siz[y];
            }
            else if(siz[y] >= sizsec) {
                thir = sec;
                sec = y; sizsec = siz[y];
            }
            else thir = y;
        }
        if(fir == -1) {
            printf("! %d\n", rt);
            fflush(stdout);
            return;
        }
        else {
            if(sec == -1) {
                printf("? %d %d\n", rt, fir);
                fflush(stdout);
                int res; scanf("%d", &res);
                if(res == 0) printf("! %d\n", rt);
                else printf("! %d\n", fir);
                fflush(stdout);
                return;
            }
            else {
                printf("? %d %d\n", fir, sec);
                fflush(stdout);
                int res; scanf("%d", &res);
                if(res == 0) {
                    dele(sec, rt);
                    dele(thir, rt);
                    del[rt] = 1; --lft;
                    rt = fir;
                }
                else if(res == 2) {
                    dele(fir, rt);
                    dele(thir, rt);
                    del[rt] = 1; --rt;
                    rt = sec;
                }
                else {
                    dele(fir, rt);
                    dele(sec, rt);
                }
            }
        }
    }
}

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