#include <bits/stdc++.h>
using namespace std;
using ll = long long;

#define x first
#define y second
#define ir(x,a,b) ((a) <= (x) && (x) <= (b))
#define pb push_back
#define all(x) (x).begin(), (x).end()
/*
#ifdef LOCAL
auto& operator<<(auto&, pair<auto, auto>);
template<typename T, typename = T::value_type>
auto& operator<<(ostream& o, T x) requires (!same_as<T, string>) {
  o << "{";
  string s;
  for (auto i : x) {
    o << s << i;
    s << ", ";
  }
  return o << "}";
}
auto& operator<<(ostream& o, pair<auto, auto> p) {
  return o << "(" << p.first << ", " << p.second << ")";
}
#define debug(x...) cerr << "["#x"]:",[](auto...$){((cerr<<" "<<$),...)<<endl;}(x)
#else
#define debug(...) 2137
#endif
*/


void add(multiset<int>& m, int x) {
	
	if(m.size() < 3) m.insert(x);
	else {
		if(*m.begin() < x) {
			m.erase(m.begin());
			m.insert(x);
		}
	}
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(nullptr);
  
  int t;
  cin >> t;
  while(t--) {
	  int n;
	  cin >> n;
	  vector<int> r(n), s(n);
	  for(int i = 0; i < n; i++) {
		cin >> r[i] >> s[i];
	  }
	  set<pair<int,int>> st;
	  multiset<int, greater<int>> ms;
	  vector<multiset<int>> v(n);
	  for(int i = 0; i < n; i++) {
		while(!st.empty() && st.begin()->first < i) {
			ms.erase(ms.find(s[st.begin()->second]));
			st.erase(st.begin());
		}
		ms.insert(s[i]);
		st.insert({i + r[i], i});
		int cnt = 0;
		for(auto it = ms.begin(); it != ms.end() && cnt < 3; it++) {
			add(v[i], *it);
			cnt++;
		}
	  }
	  ms.clear();
	  set<pair<int,int>, greater<pair<int,int>>> st2;
	  for(int i = n - 1; i >= 0; i--) {
		while(!st2.empty() && st2.begin()->first > i) {
			ms.erase(ms.find(s[st2.begin()->second]));
			st2.erase(st2.begin());
		}
		int cnt = 0;
		for(auto it = ms.begin(); it != ms.end() && cnt < 3; it++) {
			add(v[i], *it);
			cnt++;
		}
		ms.insert(s[i]);
		st2.insert({i - r[i], i});
	  }
	  
	  int ans = 0;
	  for(int i = 0; i < n; i++) {
		if(v[i].size() == 3) {
			int x = 0;
			for(auto it = v[i].begin(); it != v[i].end(); it++) x += *it;
			ans = max(ans, x);
		}
	  }
	  cout << ans <<'\n';
  }
  
  return 0;
}