#include <iostream>
#include <vector>
using namespace std;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

struct Dinic {
  struct Edge {
    int to, rev;
    ll c, oc;
    ll flow() { return max(oc - c, 0LL); } // if you need flows
  };
  vi lvl, ptr, q;
  vector<vector<Edge>> adj;
  Dinic(int n) : lvl(n), ptr(n), q(n), adj(n) {}
  void addEdge(int a, int b, ll c, ll rcap = 0) {
    adj[a].push_back({b, sz(adj[b]), c, c});
    adj[b].push_back({a, sz(adj[a]) - 1, rcap, rcap});
  }
  ll dfs(int v, int t, ll f) {
    if (v == t || !f)
      return f;
    for (int &i = ptr[v]; i < sz(adj[v]); i++) {
      Edge &e = adj[v][i];
      if (lvl[e.to] == lvl[v] + 1)
        if (ll p = dfs(e.to, t, min(f, e.c))) {
          e.c -= p, adj[e.to][e.rev].c += p;
          return p;
        }
    }
    return 0;
  }
  ll calc(int s, int t) {
    ll flow = 0;
    q[0] = s;
    rep(L, 0, 31) do { // 'int L=30' maybe faster for random data
      lvl = ptr = vi(sz(q));
      int qi = 0, qe = lvl[s] = 1;
      while (qi < qe && !lvl[t]) {
        int v = q[qi++];
        for (Edge e : adj[v])
          if (!lvl[e.to] && e.c >> (30 - L))
            q[qe++] = e.to, lvl[e.to] = lvl[v] + 1;
      }
      while (ll p = dfs(s, t, LLONG_MAX))
        flow += p;
    }
    while (lvl[t])
      ;
    return flow;
  }
  bool leftOfMinCut(int a) { return lvl[a] != 0; }
};

void solve() {
  int n, m;
  cin >> n >> m;
  vector<ll> limits(n + 1);
  ll su = 0;
  for (int i = 1; i <= n; i++) {
    cin >> limits[i];
    su += limits[i];
  }
  Dinic d(n + m + 2);
  for (int i = 1; i <= n; i++) {
    d.addEdge(i, n + m + 1, limits[i]);
  }
  vector<pair<int, int>> edgelookup(m + 1);
  for (int i = 1; i <= m; i++) {
    d.addEdge(0, n + i, 1);
    int u, v;
    cin >> u >> v;
    edgelookup[i].first = d.adj[n + i].size();
    d.addEdge(n + i, u, 1);
    edgelookup[i].second = d.adj[n + i].size();
    d.addEdge(n + i, v, 1);
  }
  d.calc(0, n + m + 1);
  ll ans = 0;
  vector<int> sans(m);
  for (int i = 1; i <= m; i++) {
    Dinic::Edge utv = d.adj[n + i][edgelookup[i].second];
    Dinic::Edge vtu = d.adj[n + i][edgelookup[i].first];
    if (utv.flow() == 1) {
      sans[i - 1] = 0;
    } else if (vtu.flow() == 1) {
      sans[i - 1] = 1;
    } else {
      sans[i - 1] = 1;
      ans++;
    }
  }
  cout << ans << endl;
  for (int x : sans) {
    cout << x;
  }
  cout << endl;
}
int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
  int t;
  cin >> t;
  while (t--)
    solve();
}

answer.code: In member function ‘ll Dinic::calc(int, int)’:
answer.code:50:31: error: ‘LLONG_MAX’ was not declared in this scope
   50 |       while (ll p = dfs(s, t, LLONG_MAX))
      |                               ^~~~~~~~~
answer.code:3:1: note: ‘LLONG_MAX’ is defined in header ‘<climits>’; did you forget to ‘#include <climits>’?
    2 | #include <vector>
  +++ |+#include <climits>
    3 | using namespace std;