#include <bits/stdc++.h>

using namespace std;

int maze[3][100005];

int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n;
        memset(maze,0,sizeof(maze));
        scanf("%d",&n);
        int maxlen = -1;
        for(int i=1; i<=n; i++)
        {
            int x,y;
            scanf("%d%d",&x,&y);
            maze[x][y] = 1;
            maxlen = max(maxlen,y);
        }
        if(maze[1][maxlen] == 1)
        {
            if(maze[2][maxlen] == 1 || maze[2][maxlen-1] == 1)
                printf("%d\n",maxlen+2);
            else
                printf("%d\n",maxlen+1);
        }
        else if(maze[2][maxlen] == 1)
            printf("%d\n",maxlen+2);
    }
    return 0;
}