#include<bits/stdc++.h>
#define ls ch[x][0]
#define rs ch[x][1]
#define ll long long
using namespace std;

inline ll read(){
    ll num=0,neg=1;char c=getchar();
    while(!isdigit(c)){if(c=='-')neg=-1;c=getchar();}
    while(isdigit(c)){num=(num<<3)+(num<<1)+c-'0';c=getchar();}
    return num*neg;
}

int n,T,ans;
bool l[100010],r[100010];

int main(){
    T=read();
    while(T--)
    {
        n=read();memset(l,0,sizeof(l)),memset(r,0,sizeof(r));
        for(int i=1;i<=n;i++){
            int op=read();
            if(op==1) r[read()]=1;
            else l[read()]=1;
        }ans=0;
        for(int i=1;i<=100000;i++)
        {
            if(l[i]){
                if(r[i+1]) ans=max(ans,i+3);
                else ans=max(ans,i+2);
            }
            if(r[i]) ans=max(ans,i+1);
        }printf("%d\n",ans);
    }return 0;
}