#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
#define mod 1000000007
int main()
{
	ll t;
	cin>>t;
	assert(t<=10);
	while(t--)
	{
		ll m,n;
		cin>>m>>n;
		assert(m>0 and m<=100000);
		assert(n>0 and n<=100000);
		ll a[m],b[m],asum=0,bsum=0;
		for(ll i=0;i<m;i++)
		{
			cin>>a[i];
			assert(a[i]<=1e9);
			asum=(asum%mod+a[i]%mod)%mod;
		}

		for(ll i=0;i<m;i++)
		{
			cin>>b[i];
			assert(b[i]<=1e9);
			bsum=(bsum%mod+b[i]%mod)%mod;
		}
		asum=((asum%mod)*(m%mod))%mod;
		bsum=((bsum%mod)*(m%mod))%mod;
		ll fib[n+1];
		memset(fib,0,sizeof(fib));
		fib[1]=asum;
		fib[2]=bsum;
		for(ll i=3;i<=n;i++)
		{
			fib[i]=(fib[i-1]%mod+fib[i-2]%mod)%mod;
		}
		cout<<fib[n]<<endl;
	}
	

}