#include<bits/stdc++.h>
using namespace std;
int main()
{
	long long t,n,x;
	cin>>t;
	while(t--)
	{
		cin>>n>>x;
		long long a[n+1],m=30,j,s=0,k,c;
		for (long long i = 0; i < n; ++i)
		{
			cin>>a[i];
			k=a[i];
			c=0;
			while(k%x==0)
			{
				k/=x;
				c++;
			}
			if (m>c)
				m=c,j=i;
		}
		//cout<<m<<" "<<j<<endl;
		for (long long i = 0; i < n; ++i)
		{
			s+=(m+1)*a[i];
		}
		for (long long i = 0; i < j; ++i)
		{
			s+=a[i];
		}
		cout<<s<<endl;
	}
}