func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 100005;   bool prime[N + 5];   int vis[11111];   int main() {     int tc = 1;     cin >> tc;     while (tc--) {       int n;       int m;       cin >> n >> m;       int ara[n + 1];       for (int i = 0; i < n; i++) {         cin >> ara[i];       }       if (m < n || n == 2) {         cout <<  -1  << endl;         continue;       } else {         int sum = 0;         for (int i = 0; i < n - 1; i++) {           sum += ara[i];           sum += ara[i + 1];         }         sum += ara[n - 1];         sum += ara[0];         cout << sum << endl;         for (int i = 1; i < n; i++) {           cout << i <<     << i + 1 << endl;         }         cout << 1 <<     << n << endl;       }     }   }   