#include <bits/stdc++.h>
#define ll long long int
#define pb push_back
#define mp make_pair
#define mod 1000000007
#define pi 3.141592653589793
const int N = 100001;
using namespace std;


int f(ll n) {
	return (1 + sqrt(1 + 8 * n)) / 2;
}


int main() {
//    cout << fixed << setprecision(10);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);


    int t;
	cin >> t;
	while (t--) {
		int n, p;
		cin >> n >> p;
		bool vis[n];
		memset(vis, false, sizeof vis);
		pair<int, int> a[n];
		int ar[n];
		for (int i = 0; i < n; i++) {
			cin >> a[i].first;
			a[i].second = i;
			ar[i] = a[i].first;
		}
		sort(a, a + n);
		ll ans = 0;
		int comp = 0;
		for (auto [e, i] : a) {
			if (vis[i]) continue;
			int h = min(e, p);
			comp++;
			int j = i - 1;
			while (j >= 0 && ar[j] % e == 0 && !vis[j]) {
				vis[j--] = 1;
				vis[i] = 1;
				ans += h;
			}
			j = i + 1;
			while (j < n && ar[j] % e == 0 && !vis[j]) {
				vis[j++] = 1;
				vis[i] = 1;
				ans += h;
			}
		}
		cout << ans + (ll) (comp - 1) * p << '\n';
	}
}

// 4 5
// 5 2 4 9