#include <cstdio>
#include <string>
#include <set>
#include <vector>
#include <algorithm>

using namespace std;

int n;
int a,b1,b2;
int main()
{
    int T,x,y;
    scanf("%d",&T);
    while(T--){
        a = b1 = b2 = -1;
        scanf("%d",&n);
        for( int i = 1; i <= n; i++ ) {
            scanf("%d%d",&x,&y);
            if( x == 1 ){
                a = max( a , y );
            }
            else{
                if ( y > b1 )
                    b2 = b1 , b1 = y;
                else b2 = max( b2 , y );
            }
        }
        if ( a == -1 ) printf("%d\n",b1+2);
        else if ( b1 == -1 ) printf("%d\n",a+1);
        else{
            if ( a == b1 + 1 ) printf("%d\n",b1+3);
            else printf("%d\n",max(b1+2 , a+1) );
        }
    }
    return 0;
}