func_code_string: #include <bits/stdc++.h>   using namespace std;   void my_dbg() { cout << endl; }   template <typename Arg, typename... Args>   void my_dbg(Arg A, Args... B) {     cout <<     << A;     my_dbg(B...);   }   using ll = long long;   using vi = vector<int>;   using vl = vector<ll>;   using pii = pair<int, int>;   const int inf = INT_MAX;   const int ninf = INT_MIN;   const int mod = 1e9 + 7;   const int maxN = 2e5 + 2;   void solve() {     int n, m;     scanf( %d , &n);     scanf( %d , &m);     vector<pii> a(m);     for (int i = (int)(0); i < (int)(m); i++) {       scanf( %d , &a[i].first);       scanf( %d , &a[i].second);     }     sort(a.begin(), a.end(), [&](pii a, pii b) { return a.second < b.second; });     ll sum = 0, ans = 0;     multiset<int> ms;     for (int i = (int)(0); i < (int)(m); i++) {       while ((int)ms.size() and              (*ms.begin() < a[i].second or (int) ms.size() >= n)) {         sum -= *ms.begin();         ms.erase(ms.begin());       }       sum += a[i].first;       ll cur = sum;       ll rem = n - (int)ms.size() - 1;       cur += rem * a[i].second;       ans = max(ans, cur);       ms.insert(a[i].first);     }     printf( %lld n , ans);   }   int main() {     int t = 1;     scanf( %d , &t);     while (t--) {       solve();     }     return 0;   }   