re.cpp

/*              |\ | |  ||\ \ /(_~     |~)|_~|\/||_~|\/||~)|_~|~)
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*/                              
#include<bits/stdc++.h>
using namespace std;
 
#define fastio ios_base::sync_with_stdio(0); cin.tie(0)
#define LL long long 
#define mod 1000000007 
#define FOR(i, j, k) for (int i=j ; i<k ; i++)
#define ROF(i, j, k) for (int i=j ; i>=k ; i--) 
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false); debug("%s time : %.4fs", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))

const long long INF = 1e18;
const long long MAX = 1e5+10;
int main(){
    fastio;
    int t=1; cin>>t;
    while(t--){
        int n; cin>>n; vector<int>v;
        LL sum =0;
        FOR(i,0,n){
            int x,y; cin>>x>>y;
            sum+=(y/4)*x*4;
            if(y%4>1) v.push_back(x);
        }
        sort(v.begin(),v.end(),greater<int>());
        for(int i=0;i<v.size()-1;i+=2) sum+=2*(v[i]+v[i+1]);
        cout<<sum<<"\n";
    }
}