/ WALL
// Wall
// Author: Constantine Sokol
// Complexity : O( M )
// Expected Verdict: AC

#include <cstdio>
#include <cstring>
#include <vector>

using namespace std;

const int maxn = 1000000000;
const int maxm = 524288 + 5;

int n, m, d[ maxm ], visited[ maxm ], coefficient[ maxm ];
long long h, w;
int a, b, x;
vector< int > order;

void solve1()
{
    scanf("%lld", &h);
    scanf("%d", &n);
    for ( int i = 0; i < n; i++ )
    {
        long long x; scanf("%lld", &x);
        w = x;
    }
    long long area = w * h;
    printf("%lld.%d\n", area / 2, area % 2 ? 5 : 0 );
}

int generate_next( int x )
{
    return (int)( ( (long long)a * x + b ) % m );
}

void solve_testcase()
{
    scanf("%lld", &h);
    scanf("%d%d", &n, &m);
    scanf("%d%d%d", &a, &b, &x);
    for ( int i = 0; i < m; i++ ) scanf("%d", &d[i]);
    memset( visited, -1, sizeof( visited ) );
    memset( coefficient, 0, sizeof( coefficient ) );
    order.clear();   
    w = 0;
    bool flag = false;
    for ( int i = 2; i <= n; )
    {
        if ( visited[ x ] == -1 || flag )
        {
            order.push_back( x );
            visited[ x ] = i;
            coefficient[ x ] += 1;
            x = generate_next( x );
            i += 1;
            continue;
        }
        int left = n - i + 1;
        int cycle_length = i - visited[ x ];
        int number = left / cycle_length;
        for ( int j = 0; j < cycle_length; j++ )
        {
            coefficient[ order.back() ] += number;
            order.pop_back();
        }
        i += cycle_length * number;
        flag = true;
    }
    for ( int i = 0; i < m; i++ ) w += (long long)coefficient[i] * d[i];
    long long area = w * h;
    printf("%lld.%d\n", area / 2, area % 2 ? 5 : 0 );
}

int main()
{
    int T; scanf("%d", &T);
    while ( T-- ) solve_testcase();
    return 0;
}