func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long INF = 1e18;   const int32_t M = 1e9 + 7;   const int32_t MM = 998244353;   long long m, n;   void solve() {     cin >> n >> m;     bool visited[n + 5];     memset(visited, 0, sizeof(visited));     for (long long i = 0; i < m; i++) {       long long a, b, c;       cin >> a >> b >> c;       visited[b] = 1;     }     long long node = -1;     for (long long i = 1; i < n + 1; i++)       if (!visited[i]) {         node = i;         break;       }     for (long long i = 1; i < n + 1; i++) {       if (i == node) continue;       cout << node <<     << i <<   n ;     }   }   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long t;     cin >> t;     while (t--) solve();   }   