#include <bits/stdc++.h>
using namespace std;
int solve()
{
    int n;cin>>n;
    vector<int> a(n+1);
    int ans=1e9;
    for(int i=1;i<=n;i++)cin>>a[i],ans=min(ans,a[i]);
    vector<vector<int>> ve(n+1);
    for(int i=1;i<n;i++){
        int x,y;cin>>x>>y;
        ve[x].push_back(y);
        ve[y].push_back(x);
    }
    vector<int> mx(n+1,1e9),mi(n+1,1e9);
    auto gmin = [&](int &x,int y){
        if(y<x)x=y;
    };
    function<void(int,int)>dfs = [&](int x,int h){
        int mxx=1e9,mii=1e9;
        for(auto it:ve[x])if(it!=h){
            dfs(it,x);
            gmin(mx[x],mx[it]+1);
            gmin(mi[x],mi[it]+1);
            gmin(ans,mx[x]+mii);
            gmin(ans,mi[x]+mxx);
            gmin(mii,mi[it]);
            gmin(mxx,mx[it]);
        }
        gmin(ans,mx[x]+a[x]);
        gmin(ans,mi[x]-a[x]);
        gmin(mx[x],1-a[x]);
        gmin(mi[x],1+a[x]);
    };
    dfs(1,0);
    return ans;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;cin>>T;while(T--)cout<<solve()<<"\n";
    return 0;
}