#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const int N = 200 + 7;
const int INF = (int) 1e9;
int p[N];
int dist[N][N];
int n, m, s, t;

struct Edge {
  int x;
  int y;
  int v;
};

bool operator < (Edge a, Edge b) {
  return a.v > b.v;
}

bool vis[N][N];

void solve() {
  cin >> n >> m >> s >> t;
  for (int i = 1; i <= n; i++) {
    cin >> p[i];
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      dist[i][j] = INF;
      vis[i][j] = 0;
    }
  }
  for (int i = 1; i <= m; i++) {
    int x, y;
    cin >> x >> y;
    dist[x][y] = p[y];
  }
  for (int k = 1; k <= n; k++) {
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
      }
    }
  }
  if (dist[s][t] == INF) {
    cout << "-1\n";
    return;
  }
  priority_queue<Edge> pq;
  pq.push({s, s, p[s]});
  while (!pq.empty()) {
    Edge e = pq.top();
    pq.pop();
    if (vis[e.x][e.y]) continue;
    vis[e.x][e.y] = 1;
    if (e.x == t && e.y == t) {
      cout << e.v << "\n";
      return;
    }
    if (!vis[e.y][e.x]) {
      pq.push({e.y, e.x, e.v + dist[e.x][e.y] - p[e.x]});
    }
    for (int k = 1; k <= n; k++) {
      pq.push({k, e.y, e.v + dist[e.x][k] - p[k] * (e.y == k)});
      pq.push({e.x, k, e.v + dist[k][e.y] - p[k] * (e.x == k)});
    }
  }
}

signed main() {
#ifdef ONPC
  freopen("input.txt", "r", stdin);
#else
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#endif // ONPC

  int tt;
  cin >> tt;
  while (tt--) {
    solve();
  }
  return 0;
}