#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <set>
#include <vector>
#include <utility>
#include <stack>
#include <deque>
#include <queue>
#include <string>
#include <cctype>
#include <ctime>
#include <sstream>
#include <map>
//#define LOCAL
#define ll long long
#define maxn 100010
#define maxw 1000005
#define INF 1000000000000000000
using namespace std;

ll n;

int main()
{
#ifdef LOCAL
    freopen("data.in.txt", "r", stdin);
    freopen("data.out.txt", "w", stdout);
#endif
    int t; cin >> t;
    while(t--)
    {
        scanf("%lld", &n);
        ll maxy[2] = {0, 0};
        for(int i = 0; i < n; i++)
        {
            int x; ll y;
            scanf("%d%lld", &x, &y);
            maxy[x-1] = max(maxy[x-1], y);
        }
        ll ans = 0;
        if(maxy[0] == 0) ans = maxy[1]+2;
        else if(maxy[1] == 0) ans = maxy[0]+1;
        else if(maxy[0] > maxy[1])
            ans = max(maxy[0]+1, maxy[1]+3);
        else
            ans = maxy[1]+2;
        cout << ans << endl;
    }
    return 0;
}