#include<bits/stdc++.h>
using namespace std;
vector<int>a,b;
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        int n;
        scanf("%d",&n);
        int t=1e9;
        a.clear();b.clear();
        for(int i=0;i<n;i++){
            int x,y;
            scanf("%d%d",&x,&y);x=3-x;
            if(x&1)a.push_back(y);
            else b.push_back(y);
        }
        sort(a.begin(),a.end());
        sort(b.begin(),b.end());
        int tl=0,tr=0;
        if(a.size())tl=a[a.size()-1];
        if(b.size())tr=b[b.size()-1];
        if(tl==0)t=tr+1;
        else if(tr==0)t=tl+2;
        else{
            if(tl+1==tr)t=tl+3;
            else t=max(tl+2,tr+1);
        }
        printf("%d\n",t);
    }    
}