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


int main()
{
    int test,i,j,k,t,n,ans,count,a,b,c;
    cin>>t;
    while(t--)
    {
         ans=0;
        cin>>n>>b;
        while(b--)
        {
            count=1;
            cin>>a;
            while(a--)
            {
                cin>>c;
                count*=c;
                count%=n;
            }
            ans+=count;

        }
        cout<<ans%n<<endl;
    }
    return 0;
}