#include<bits/stdc++.h>
using namespace std;

struct node{
    int val;
    int cnt;
};

bool cmp(node a, node b){
    return a.val < b.val;
}

int cal(int n){
    return n*(n+1)/2;
}

int main()
{
    int T;
    scanf("%d", &T);
    while(T--){
        node s[26];
        memset(s, 0, sizeof(s));
        int n, sum = 0;
        scanf("%d", &n);
        for (int i = 0; i < n; ++i)
            scanf("%d%d", &s[i].val, &s[i].cnt);
        sort(s, s+n, cmp);
        int ans = 0, first;
        for (int i = 0; i < n; ++i){
            if (s[i].val >= 0){
                first = i;
                break;
            }
        }
        int temp = 0;
        for (int i = first; i < n; ++i){
            int num = cal(s[i].cnt+sum) - cal(sum);
            sum += s[i].cnt;
            ans += num * s[i].val;
            temp += s[i].val * s[i].cnt;
        }
        for (int i = first - 1; i >= 0; --i){
            if (temp + s[i].val > 0){
                int cc = s[i].cnt;
                while(cc--){
                    if (temp + s[i].val <= 0) break;
                    temp += s[i].val;
                    ans += temp;
                }
            }
            else break;
        }
        printf("%d\n", ans);
    }

    return 0;
}