#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
const int MAXN = 1e5 + 10;

int x[MAXN], y[MAXN];

int main()
{
    int T;
    scanf("%d", &T);
    while (T--)
    {
        for (int i = 1; i <= 100000; i++)
            x[i] = y[i] = 0;
        int n, mx = 0;
        scanf("%d", &n);
        for (int i = 0; i < n; i++)
        {
            int a, b;
            scanf("%d%d", &a, &b);
            if (a == 2)
                x[b] = 1;
            else
                y[b] = 1;
            mx = max(mx, b);
        }
        int ans = 0;
        for (int i = 1; i <= 100000; i++)
        {
            if (x[i] + y[i] == 2)
            {
                if (y[i + 1] == 1)
                {
                    ans = max(ans, i + 3);
                }
                else
                {
                    ans = max(ans, i + 2);
                }
            }
            else
            {
                if (x[i] == 1)
                {
                    if (i == mx){
                        ans = max(ans, i + 2);    
                    }
                    else{
                        ans = max(ans, i + 3);
                    }
                }
                if (y[i] == 1)
                {
                    ans = max(ans, i + 1);
                }
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}