#include <bits/stdc++.h>
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define f first
#define s second
using namespace std;
using ll = long long;
using pii = pair <int, int>;
const int N = 1e6 + 5, inf = 1e9;
int n, a[N], sz[N], ans;
bool used[N];
vector <int> g[N];
void calc(int v, int p = 0) {
    sz[v] = 1;
    for (auto to : g[v]) {
        if (!used[to] && to != p)
            calc(to, v), sz[v] += sz[to];
    }
}
int center(int v, int nsz, int p = 0) {
    for (auto to : g[v]) {
        if (!used[to] && to != p && sz[to] > nsz / 2)
            return center(to, nsz, v);
    }
    return v;
}
int dist[N], mx[N], mn[N];
vector <int> nodes;
void go(int v, int p = 0) {
    nodes.pb(v);
    ans = min(ans, dist[v] + 1 - mx[v] + mn[v]);
    for (auto to : g[v]) {
        if (!used[to] && to != p) {
            dist[to] = dist[v] + 1;
            mx[to] = max(mx[v], a[to]);
            mn[to] = min(mn[v], a[to]);
            go(to, v);
        }
    }
}
void dfs(int v) {
    calc(v);
    v = center(v, sz[v]);
    used[v] = 1;
    dist[v] = 0;
    mx[v] = mn[v] = a[v];
    go(v);
    sort(all(nodes), [&] (int x, int y) {
        return mx[x] < mx[y];
    });
    int mnn = inf;
    for (auto u : nodes) {
        ans = min(ans, mnn + dist[u] - mx[u]);
        mnn = min(mnn, dist[u] + mn[u] + 1);
    }
    nodes.clear();
    for (auto to : g[v]) {
        if (!used[to]) 
            dfs(to);
    }
}
void solve() {
    cin >> n;
    ans = inf;
    for (int i = 1; i <= n; ++i) {
        g[i].clear();
        used[i] = 0;
        cin >> a[i];
    }
    for (int i = 1, u, v; i < n; ++i) {
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
    }
    dfs(1);
    cout << ans << '\n';
}
int main() {
    ios :: sync_with_stdio(false);
    cin.tie(nullptr);
    int T;
    cin >> T;
    while (T--)
        solve();
    return 0;
}