#include <bits/stdc++.h>

using namespace std;

void solve(int cs) {
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  for (int i = 0; i < n; i++) cin >> a[i];
  const int INF = 1e9;
  vector<int> dp(n, INF), f(2e5 + 5, INF);
  for (int i = 0; i < n; i++) {
    if (i == 0) dp[i] = 0;
    else {
      dp[i] = dp[i - 1] + k;
      for (int j = 1; j * j <= a[i]; j++) {
        if (a[i] % j == 0) {
          dp[i] = min(dp[i], f[j]);
          dp[i] = min(dp[i], f[a[i] / j]);
        }
      }
    }
    for (int j = 1; j * j <= a[i]; j++) {
      if (a[i] % j == 0) {
        f[j] = min(f[j], dp[i] + a[i] / j);
        f[a[i] / j] = min(f[a[i] / j], dp[i] + a[i] / (a[i] / j));
      }
    }
  }
  cout << dp[n - 1] << "\n";
}

int32_t main() {
  cin.tie(0) -> sync_with_stdio(0);
  int t = 1;
  cin >> t;
  for (int i = 1; i <= t; i++) {
    solve(i);
  }
  return 0;
}