uocsochunglonnhat

#include <bits/stdc++.h>

#define ll long long
#define pb push_back
#define pii pair<int, int>
#define pll pair<ll, ll>
#define el endl
#define umi unordered_map<int, int>
#define umll unordered_map<ll, ll>
#define all(vect) vect.begin(), vect.end()
#define reset(A) memset(A, 0, sizeof(A))
#define approx(n) fixed << setprecision(n)

using namespace std;

const int mod = 1e9 + 7;

void solve()
{
  ll n, k;
  cin >> n >> k;
  ll a[n];
  ll dp[n + 5];
  reset(dp);
  for (int i = 0; i < n; i++)
  {
    cin >> a[i];
    if (a[i] == k)
      dp[i] = 1;
  }
  if (a[0] % k == 0)
    dp[0] = 1;
  for (int i = 1; i < n; i++)
  {
    if (__gcd(a[i], a[i - 1]) == k)
    {
      dp[i] = dp[i - 1] + 1;
    }
    else
    {
      dp[i] = max(dp[i], dp[i - 1]);
    }
  }
  // for (int i = 0; i < n; i++)
  // {
  //   cout << dp[i] << " ";
  // }
  // cout << el;
  if(dp[n - 1] == 0) {
    cout << -1 << el;
    return;
  }
  cout << dp[n - 1] << el;
}

int main()
{
  int t = 1;
  cin >> t;
  // cin.ignore();
  while (t--)
  {
    solve();
  }
  return 0;
}

/*
3
8 3
6 9 7 10 12 24 36 27
4 3
2 4 6 8
4 6
1 2 3 6
*/