#include<iostream>
#include<algorithm>
#include<queue>
#include<utility>
#include<cmath>
#pragma warning(disable:4996)
#define inf 0x3f3f3f3f
typedef long long ll;
using namespace std;
ll a[1000000], b[1000000];
int main()
{
    int t;
    cin >> t;
    while (t--) {
        fill(a, a + 100004, 0);
        fill(b, b + 100004, 0);
        ll n, x=0, y=0, bl = 0, al = 0;
        cin >> n;
        for (int i = 1; i <= n; i++) {
            scanf("%lld%lld", &x, &y);
            if (x == 1) {
                b[y] = 1;
                if (y > bl) {
                    bl = y;
                }
            }
            else {
                a[y] = 1;
                if (y > al) {
                    al = y;
                }
            }
        }
        for (int i = 1; i <= al+1; i++) {
            if (a[i] == 1 && b[i + 1] == 0) {
                a[i] = 0;
                b[i + 1] = 1;
            }
        }
        ll kk;
        kk = max(al, bl);
        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) {
            cout << max(x + 3, y + 1) << endl;
        }
        else if (x == 0 && y > 0) {
            cout << y+1 << endl;
        }
    }
    return 0;
}