#include <iostream>
#include <cstring>
typedef long long LL;
using namespace std;
const int N=1000010;
LL a[N],b[N];
void solve(int n,LL x, LL y,LL lb, LL la){
    for (int i = 1;i<=la+1;i++) {
        if (a[i]==1&&(!b[i + 1])) {
            a[i] = 0;
            b[i + 1]=1;
        }
    }
    LL kk=max(la, lb);
    x=0; y=0;
    for (int i=1; i<=kk+2; i++) {
        if (a[i]==1) {
            x=i;
        }
        if (b[i]==1) {
            y=i;
        }
    }
    if (x>0&&y>0) {
        if(x+3>y+1) cout<<x+3<<endl;
        else cout<<y+1<<endl;
    }
    else if (x==0&&y> 0) {
        cout<<y+1<<endl;
    }
}
int main(){
    int T;
    cin>>T;
    while (T--) {
        memset(a,0,sizeof a);
        memset(b,0,sizeof b);
        int  n; 
        LL x=0, y=0, la = 0,lb = 0;
        cin>>n;
        for (int i = 1; i <= n; i++) {
            cin>>x>>y;
            if (x==1){
                b[y] = 1;
                if(y>lb) {
                    lb=y;
                }
            }
            else {
                a[y]=1;
                if (y>la) {
                    la=y;
                }
            }
        }
        solve(n,x,y,lb,la);
    }
    return 0;
}