#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int inf=1e9+7;
const int N=1000013;

int r[N],s[N];
vector<pair<int,int>>op[N];
void solve(){
    int n;cin>>n;
    for(int i=1;i<=n;i++)op[i].clear();

    for(int i=1;i<=n;i++) {
        cin>>r[i]>>s[i];
        int l=max(1,i-r[i]),R=min(n,i+r[i]);
        op[l].emplace_back(i,1),op[R+1].emplace_back(i,-1);
    }
    multiset<ll>pq;
    ll ans=0;
    for(int i=1;i<=n;i++) {
        for(auto[id,k]:op[i])if(k==1)pq.insert(s[id]);else pq.erase(pq.find(s[id]));
        if(pq.size()>=3) {
            ll v=0;
            auto it=pq.rbegin();
            for(int k=1;k<=3;k++)v+=*it++;
            ans=max(ans,v);
        }
    }
    cout<<ans<<'\n';
}

int main(){
    ios::sync_with_stdio(false);
    int T=1;
    cin>>T;
    while(T--)solve();
}