#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int N = 200 * 1000 + 7;
vector<int> beg[N], en[N];
int tab[N];
set<pair<int, int>> se;

inline pair<int, int> GetM()
{
	auto it = se.end(); --it;
	pair<int, int> ans = *it;
	se.erase(it);
	return ans;
}

inline int CurA()
{
	int ans = 0; if(se.size() < 3) return 0;
	pair<int, int> a, b, c;
	a = GetM(); b = GetM(); c = GetM();
	ans = a.st + b.st + c.st;
	se.insert(a); se.insert(b); se.insert(c);
	return ans;
}

void solve() 
{
	int n, r, s, ans = 0;
	cin >> n;
	for(int i = 1; i <= n; ++i)
	{
		cin >> r >> s; tab[i] = s;
		beg[max(1, i - r)].pb(i);
		en[min(n + 1, i + r + 1)].pb(i);
	}
	for(int i = 1; i <= n; ++i)
	{
		for(int j = 0; j < (int)beg[i].size(); ++j)
			se.insert(make_pair(tab[beg[i][j]], beg[i][j]));
		for(int j = 0; j < (int)en[i].size(); ++j)
			se.erase(make_pair(tab[en[i][j]], en[i][j]));
		ans = max(ans, CurA());
	}
	for(int i = 1; i <= n + 4; ++i)
	{
		beg[i].clear(); en[i].clear();
	}
	cout << ans << "\n";
	se.clear();
}

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	int _=1;
	cin >> _;
	while(_--) solve();
}