#include<bits/stdc++.h>
using namespace std;
template <typename T> inline void read(T &x)
{
	x=0;short f=1;char c=getchar();
	for(;c<'0'||c>'9';c=getchar()) if(c=='-') f=-1;
	for(;c>='0'&&c<='9';c=getchar()) x=(x<<1)+(x<<3)+(c^48);
	x*=f;return;
}
const int N=5e5+5;
int n;
vector<int>vl[N],vr[N];
multiset<int>S;
int main()
{
	int T;read(T);
	while(T--)
	{
		read(n);
		S.clear();
		for(int i=0;i<=n+1;++i)
			vl[i].clear(),vr[i].clear();
		for(int i=1;i<=n;++i)
		{
			int x,v;read(x),read(v);
			int L=max(i-x,1),R=min(i+x,n);
			vl[L].push_back(v);
			vr[R+1].push_back(v);
		}
		int ans=0;
		for(int i=1;i<=n;++i)
		{
			for(int x:vl[i]) S.insert(x);
			for(int x:vr[i]) S.erase(S.find(x));
			if(S.size()>=3)
			{
				int res=0;
				auto it=S.end();
				it=prev(it);
				res+=*it;
				it=prev(it);
				res+=*it;
				it=prev(it);
				res+=*it;
				ans=max(ans,res);
			}
		}
		printf("%d\n",ans);
	}
}