#include<bits/stdc++.h>
#define endl '\n'
#define F first
#define S second
#define pb push_back
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define error1(x) cerr<<#x<<" = "<<(x)<<endl
#define error2(a,b) cerr<<"("<<#a<<", "<<#b<<") = ("<<(a)<<", "<<(b)<<")\n";
#define coutall(v) for(auto &it: v) cout << it << " "; cout << endl;
using namespace std;
using ll = long long;
using ld = long double;
void solve() {
ll n, cnt = 0;
cin >> n;
vector<ll> val(n + 1);
for (int i = 1; i <= n; i++) {
ll x; cin >> x;
val[i] = x;
if(x) ++cnt;
}
vector<set<ll>> g(n + 1);
for(int i = 0; i + 1 < n; i++) {
ll u, v; cin >> u >> v;
g[u].insert(v);
g[v].insert(u);
}
if(cnt == 0) {
cout << 0 << endl;
return;
}
priority_queue<ll> pq;
for(int i = 1; i <= n; i++) {
if(g[i].size() == 1 && val[i] == 0) pq.push(i);
}
while(pq.size()) {
ll u = pq.top();
ll v = *g[u].begin();
// cout << u << " <= ";
pq.pop();
if(val[v] == 0) {
pq.push(v);
}
g[u].clear();
g[v].erase(u);
}
vector<ll> depth(n + 1, 0);
auto dfs2 = [&](int u, int par, int d, auto&& self) -> void {
depth[u] = d;
for(auto &i: g[u]) {
if(i == par) continue;
self(i, u, d + 1, self);
}
};
ll root = 1;
priority_queue<pair<ll, ll>> pp;
for(int i = 1; i <= n; i++) {
if(g[i].size() == 1) {
dfs2(i, -1, 0, dfs2);
break;
}
}
for(int i = 1; i <= n; i++) {
if(g[i].size() == 1) pp.push({depth[i], i});
}
ll ans = 0;
auto dfs = [&](int u, int par, int d, auto&& self) -> ll {
ll mxD = d;
for(auto &v: g[u]) {
if(v == par) continue;
// cout << u << " " << v << endl;
++ans;
mxD = max(mxD, self(v, u, d + 1, self));
++ans;
}
return mxD;
// cout << u << " => " << c << endl;
};
ll Ans = LLONG_MAX, T = 1;
while(T-- && pp.size()) {
ans = 0;
ans -= dfs(pp.top().S, -1, 0, dfs);
Ans = min(Ans, ans);
// cout << pp.top().S << " = " << ans << endl;
pp.pop();
}
if(Ans == LLONG_MAX) Ans = 0;
cout << Ans << endl;
return;
}
signed main() {
ios::sync_with_stdio(false); cin.tie(0);
int tc = 1;
cin >> tc;
for (int t = 1; t <= tc; t++) {
// cout << "Case " << t << ": ";
solve();
}
return 0;
}