#include <bits/stdc++.h>

using namespace std;
#define st first 
#define nd second 
#define pb push_back  
#define BOOST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); 
typedef long long ll;

const int MN = 200005; 
bool aktu[MN]; 
int frogs[MN];  

void solve(){ 
    int res = 0; 
    vector <pair< pair<int,int>,int>  > event;
    priority_queue<pair<int,int> > Q; 
    int r, s;  
    int n; cin >> n; 
    for(int i = 1; i <= n; i++){ 
        cin >> r >> s;  
        frogs[i] = s; 
        event.pb({ {max(1, i-r), 0}, i}); 
        event.pb({ {min(n, i+r), 1}, i});  // { { }, } 
    } 
    sort(event.begin(), event.end());  
    event.pb({{n+1, -1}, -1});  
    int ind = 0;  
    queue<pair<int, int> > pom;  
    int tymwyn = 0; 
    for(int i = 1; i <= n; i++){ 
        while(event[ind].st.st == i && event[ind].st.nd == 0){ 
            Q.push({frogs[event[ind].nd], event[ind].nd});  
            aktu[event[ind].nd] = 1; 
            ind++; 
        } 
        // tutaj liczymy wynik   
        tymwyn = 0; 
        while(!Q.empty() && pom.size() < 3){ 
            if(!aktu[Q.top().nd]){
                Q.pop();  
                continue; 
            } 
            tymwyn += frogs[Q.top().nd]; 
            pom.push(Q.top());  
            Q.pop(); 
        } 
        if(pom.size() == 3){ 
            res = max(res, tymwyn); 
        } 
        while(!pom.empty()){ 
            Q.push(pom.front()); 
            pom.pop(); 
        }  
        while(event[ind].st.st == i && event[ind].st.nd == 1){ 
            //Q.push({frogs[event[ind].nd], event[ind].nd});
            aktu[event[ind].nd] = 0; 
            ind++; 
        } 
    } 
    for(int i = 1; i <= n; i++) 
        aktu[i] = 0; 
    cout << res << "\n"; 
}

int main()
{
    BOOST
    int t; cin >> t; 
    while(t--){ 
        solve(); 
    }
}