#include <bits/stdc++.h>
using namespace std;

long long t, n,m, adj[15010], a[15010], A, B, ans = -1e9, k, val[15010];
bool viz[15010];

queue<int> q;
vector<int> v[15010];
//vector<int>::iterator it;


void sort_top(int x){
    viz[x]=1;
    for(int i = 0; i < v[x].size();i++){
        if(!viz[v[x][i]])
            sort_top(v[x][i]);
    }
    q.push(x);
}

void curatare(){

    for(int i=1;i<=n;i++){
        viz[i] = 0;
        val[i] = 0;
    }
    ans = -1e9;
    k=0;

    for(int i=1;i<=n;i++)
        v[i].clear();

}

int main(){
    ifstream cin("easygraph.in");
    ofstream cout("easygraph.out");
    cin>>t;
    while(t--){
        cin>>n>>m;
        for(int i=1;i<=n;i++){
            cin>>a[i];
            ans = max(ans, a[i]);
            val[i] = a[i];
        }
        for(int i=0;i<m;i++){
            cin>>A>>B;
            v[A].push_back(B);

        }
        for(int i=1;i<=n;i++){
            if(!viz[i]) sort_top(i);
        }
        while(!q.empty()){
            adj[k++] = q.front();
           // cout<<adj[k-1]<<' ';
            q.pop();
        }
        //cout<<'\n';
        for(int i=1;i<=n;i++)
            val[i] = a[i];
        for(int i=k-1;i>=0;i--){
            ans = max(ans, val[adj[i]]);
            if(val[adj[i]]<0) val[adj[i]] = 0;

            //cout<<val[adj[i]]<<": ";
            for(int j = 0; j < v[adj[i]].size(); j++){

                val[v[adj[i]][j]] = max(val[v[adj[i]][j]],val[adj[i]] + a[v[adj[i]][j]]);
               // cout<<val[v[adj[i]][j]]<<' ';
            }
            //cout<<'\n';

        }
        cout<<ans<<'\n';

        curatare();

    }

    return 0;
}