#include <bits/stdc++.h>

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;



void solve()
{
	int n;
	cin >> n;
	
	
	vector<VI> add(n), remove(n + 1);
	FOR(i, 0, n)	
	{
		int r, s;
		cin >> r >> s;
		add[max(0, i - r)].PB(s);
		remove[min(n, i + r + 1)].PB(s);
	}
	int ans = -1;
	multiset<int> skills;
	FOR(i, 0, n)
	{
		for(int s : add[i])
			skills.insert(s);
		for(int s : remove[i])
			skills.erase(skills.find(s));
		
		if(SZ(skills) >= 3)
		{
			auto it = skills.end();
			int cur = 0;
			FOR(t, 0, 3)
			{
				it--;
				cur += *it;
			}
			
			ans = max(ans, cur);
		}
	}
	cout << ans << "\n";
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	int t;
	cin >> t;
	while(t--)
		solve();
	
	
	return 0;
}