#include <bits/stdc++.h>
using namespace std;
#ifndef _LOCAL
//#pragma GCC optimize("O3,Ofast")
#else
#pragma GCC optimize("O0")
#endif
template<typename t> inline void umin(t &a, const t b) {a = min(a, b);}
template<typename t> inline void umax(t &a, const t b) {a = max(a, b);}
typedef long long ll;
#define int ll
typedef pair<int, int> pii;
typedef long double ld;
ll time() {return chrono::system_clock().now().time_since_epoch().count();}
mt19937 rnd(time());
#define ft first
#define sd second
#define len(f) int((f).size())
#define bnd(f) (f).begin(), (f).end()
#define _ <<' '<<
const int inf = 1e9 + 5;
const ll inf64 = 4e18 + 5;
const int md = 998244353;
namespace MD {
void add(int &a, const int b) {if((a += b) >= md) a -= md;}
void sub(int &a, const int b) {if((a -= b) < 0) a += md;}
int prod(const int a, const int b) {return ll(a) * b % md;}
};
const int N = 4e5 + 5;
int n;
list<int> g[N];
int tin[N], tout[N], timer, si[N];
void init(int v = 0, int pr = -1) {
tin[v] = timer++;
si[v] = 1;
g[v].remove(pr);
for(int u : g[v])
init(u, v),
si[v] += si[u];
tout[v] = timer++;
}
set<int> f, w;
int dfs(int v = 0) {
int a = si[v];
int res = +inf;
if(!f.empty()) {
auto it = f.lower_bound(a + (n - a >> 1));
if(it != f.end()) {
int b = *it - a;
int c = n - a - b;
if(b > c) swap(b, c);
umin(res, max(abs(b - c), max(
abs(a - b),
abs(a - c))));
}
if(it != f.begin()) {
int b = *--it - a;
int c = n - a - b;
if(b > c) swap(b, c);
umin(res, max(abs(b - c), max(
abs(a - b),
abs(a - c))));
}
}
if(!w.empty()) {
auto it = w.lower_bound(n - a >> 1);
if(it != w.end()) {
int b = *it;
int c = n - a - b;
if(b > c) swap(b, c);
umin(res, max(abs(b - c), max(
abs(a - b),
abs(a - c))));
}
if(it != w.begin()) {
int b = *--it;
int c = n - a - b;
if(b > c) swap(b, c);
umin(res, max(abs(b - c), max(
abs(a - b),
abs(a - c))));
}
}
if(!g[v].empty()) {
f.insert(a);
for(int u : g[v])
umin(res, dfs(u));
f.erase(a);
}
w.insert(a);
return res;
}
void solve() {
cin >> n;
for(int i = 1; i < n; ++i) {
int x, y;
cin >> x >> y;
--x, --y;
g[x].push_back(y);
g[y].push_back(x);
}
init();
cout << dfs() << endl;
#ifdef KEK
timer = 0;
for(int i = 0; i < n; ++i)
g[i].clear();
f.clear();
w.clear();
#endif // KEK
}
signed main() {
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#ifndef _LOCAL
// freopen("file.in", "r", stdin);
// freopen("file.out", "w", stdout);
#else
system("color a");
freopen("in.txt", "r", stdin);
int t; cin >> t;
while(t--)
#endif
solve();
}
