func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, t;   int main() {     cin >> t;     while (t--) {       int s = 0, a;       cin >> n >> m;       for (int i = 1; i <= n; i++) {         cin >> a;         s += 2 * a;       }       if (m < n || n < 3) {         cout << -1 << endl;         continue;       }       cout << s << endl;       for (int i = 1; i < n; i++) cout << i <<     << i + 1 << endl;       cout << n <<     << 1 << endl;     }   }   