#include <cstdio>
#include <utility>
#include <algorithm>
#include <queue>

int t;
int n,m;
std::pair<int,int> data[30];

long long work(int x)
{
    int i,j,k;
    long long answer = 0;

    for(i = 0;i < n && x;++i)
    {
        k = data[i].second;
        if(k > x)
            k = x;
        answer += (x + x - k + 1) * k / 2 * data[i].first;
        x -= k;
    }

    return answer;
}

long long solve(void)
{
    int l,r;
    int x1,x2;
    long long m1,m2;
    long long answer = 0;

    l = 0;
    r = m;

    while(l < r)
    {
        x1 = l + (r - l) / 3;
        x2 = r - (r - l) / 3;
        m1 = work(x1);
        m2 = work(x2);

        answer = std::max(answer,std::max(m1,m2));

        if(m1 == m2)
            l = x1 + 1,r = x2 - 1;
        else if(m1 > m2)
            r = x2 - 1;
        else if(m1 < m2)
            l = x1 + 1;
    }

    return answer;
}

int main(void)
{
    int i,j,k;
    int answer;

    //freopen("x.in","r",stdin);

    scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        m = 0;
        for(i = 0;i < n;++i)
            scanf("%d %d",&data[i].first,&data[i].second),m += data[i].second;

        std::sort(data,data + n,std::greater<std::pair<int,int> >());

        printf("%I64d\n",solve());
    }

    return 0;
}