#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        ll n,k,sum=0;
        cin>>n>>k;
        for(int i=0; i<n; i++)
        {
            ll p;
            cin>>p;
            sum+=p%k;
        }
        cout<<sum%k<<endl;
    }
}