#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<vector>
#include<map>
using namespace std;
int main()
{

  int T;
  scanf("%d",&T);
  while(T--)
  {
    int n;
    scanf("%d",&n);
    int x=-1,y=-1;
    for(int i=0;i<n;i++)
    {
        int a,b;
        scanf("%d%d",&a,&b);
        if(a==1)//you
           y = max(y,b);
        else if (a==2) // zuo
           x = max(x,b);
    }
    //int q = 100000;
    //printf("%d\n",q+2);
    if (x>=y)
    {
        x+=2;
        printf("%d\n",x);
    }
    else
    {
        if (y==1+x)
        {
            y+=2;
            printf("%d\n",y);
        }
        else
        {
            y+=1;
            printf("%d\n",y);
        }
    }
  }
      return 0;
}