#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef vector<ll> vll;

const ll inf = 1e18;


struct Entry
{
	Entry()
	{
		val[0] = -inf;
		val[1] = -inf;
		val[2] = -inf;
	}
	array<ll, 3> val;
	void operator+=(ll x)
	{
		if (x >= val[0])
		{
			val[2] = val[1];
			val[1] = val[0];
			val[0] = x;
		}
		else if (x >= val[1])
		{
			val[2] = val[1];
			val[1] = x;
		}
		else if (x >= val[2])
		{
			val[2] = x;
		}
	}
};

vector<Entry> t;
ll tsize;

void add(int l, int r, ll x)
{
	for (l += tsize, r += tsize; r > l; r >>= 1, l >>= 1)
	{
		if (l & 1)
		{
			t[l] += x;
			l++;
		}
		if (r & 1)
		{
			r--;
			t[r] += x;
		}
	}
}

ll query(int pos)
{
	Entry ret;
	for (pos += tsize; pos > 0; pos >>= 1)
	{
		ret += t[pos].val[0];
		ret += t[pos].val[1];
		ret += t[pos].val[2];
	}
	return ret.val[0] + ret.val[1] + ret.val[2];
}


int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int tc;
	cin >> tc;
	while (tc--)
	{
		ll n;
		t.clear();
		cin >> n;
		tsize = 1;
		while (n > tsize)
		{
			tsize *= 2;
		}
		t.resize(2 * tsize);
		for (ll i = 0; i < n; i++)
		{
			ll r, s;
			cin >> r >> s;
			ll l = max(0ll, i - r);
			ll rr = min(n, i + r + 1ll);
			add(l, rr, s);
		}
		ll ret = -inf;
		for (int i = 0; i < n; i++)
		{
			ret = max(ret, query(i));
		}
		cout << ret << '\n';
	}
}