#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;
using u128 = unsigned __int128;

void solve() {
    int n, m;
    std::cin >> n >> m;
    
    std::vector<int> a(m), b(m), c(m);
    for (int i = 0; i < m; i++) {
        std::cin >> a[i] >> b[i] >> c[i];
        a[i]--;
        b[i]--;
    }
    
    std::vector<int> d(n);
    for (int i = 0; i < n; i++) {
        std::cin >> d[i];
    }
    
    std::vector<std::array<int, 2>> ans;
    for (int i = 0; i < n; i++) {
        if (d[i] == 0) {
            ans.push_back({i + 1, 1});
        }
    }
    std::vector<std::vector<int>> adj(n);
    std::vector<int> deg(n);
    for (int i = 0; i < m; i++) {
        if (d[a[i]] != d[b[i]]) {
            if (c[i] == d[a[i]]) {
                adj[a[i]].push_back(b[i]);
                deg[b[i]]++;
            } else {
                adj[b[i]].push_back(a[i]);
                deg[a[i]]++;
            }
        }
    }
    
    std::vector<int> q;
    for (int i = 0; i < n; i++) {
        if (deg[i] == 0) {
            q.push_back(i);
        }
    }
    for (int i = 0; i < q.size(); i++) {
        int x = q[i];
        for (auto y : adj[x]) {
            if (--deg[y] == 0) {
                q.push_back(y);
            }
        }
    }
    if (q.size() != n) {
        std::cout << "NO\n";
        return;
    }
    for (auto i : q) {
        ans.push_back({i, d[i]});
    }
    
    std::cout << "YES\n";
    std::cout << ans.size() << "\n";
    for (auto [x, y] : ans) {
        std::cout << x << " " << y << "\n";
    }
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int t;
    std::cin >> t;
    
    while (t--) {
        solve();
    }
    
    return 0;
}