#include<iostream>
#include<stdio.h>
#include<algorithm>
using namespace std;
#define maxn 3000
typedef long long LL;
LL n,m,k,l,s,t,r,T,ans;
struct st
{
    LL num,val;
}node[maxn];

LL a[maxn];
LL cmp(st x,st y)
{
    return x.val>y.val;
}
int main()
{
    LL i,j;
    cin>>T;
while(T--)
{
    scanf("%I64d",&n);
        for(i=1;i<=n;i++)
        {
            scanf("%I64d %I64d",&node[i].val,&node[i].num);
        }
    ans=0;t=0;
    sort(node+1,node+1+n,cmp);
    LL pre=0;
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=node[i].num;j++)
            if(ans<ans+pre+node[i].val)
            {
                ans=ans+pre+node[i].val;
                pre+=node[i].val;    
                //cout<<ans<<endl;
            }
        
    }
    //cout<<"t="<<t<<endl;
    printf("%I64d\n",ans);    
}
    return 0;
}