#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n,time;
        cin>>n;
        int maxzuo=0,maxyou=0;
        for(int i=0;i<n;++i)
        {
            int x,y;
            cin>>x>>y;
            if(x==1)
                maxyou=max(maxyou,y);
            else
                maxzuo=max(maxzuo,y);
        }
        if(maxzuo==0)
        {
            cout<<maxyou+1<<endl;
            continue;
        }
        if(maxyou==0)
        {
            cout<<maxzuo+2<<endl;
            continue;
        }
        if(maxyou==maxzuo+1)
            time=maxyou+2;
        else if(maxyou>maxzuo)
            time=maxyou+1;
        else
            time=maxzuo+2;
        cout<<time<<endl;
    }
    return 0;
}