#include<iostream>
#include<cmath>
#include<cstdio>
#include<string>
#include<cstring>
#include<algorithm>
#define ll long long
using namespace std;
int t,n,m[3][101000]={0};
int main(){
    scanf("%d",&t);
    for(int ti=1;ti<=t;ti++){
        scanf("%d",&n);
        memset(m,0,sizeof(m));
        int ml=0,mr=0;
        for(int i=1;i<=n;i++){
            int x,y;
            scanf("%d%d",&x,&y);
            m[x][y]=1;
            if(x==1)
            mr=max(mr,y);
        }
        for(int i=100000;i>=1;i--){
            if(m[2][i]==1){
                if(m[1][i+1]==0){
                    m[2][i]=0;m[1][i+1]=1;
                    mr=max(mr,i+1);
                }
                else{
                    ml=max(ml,i);
                }
            }
        }
        for(int i=100000;i>=1;i--){
            if(m[1][i]==1){
                mr=i;break;
            }
        }
        for(int i=100000;i>=1;i--){
            if(m[2][i]==1){
                ml=i;break;
            }
        }
        int a=ml+3,b=mr+1;
        if(ml!=0)
        cout<<max(a,b)<<endl;
        else{
            cout<<b<<endl;
        }
    }
    return 0;
}