#include <bits/stdc++.h>

/*#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")*/

using namespace std;

#define pb push_back
#define sz size()
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define int long long

typedef pair < int, int > pii;
typedef vector < int >  vi;
typedef vector < vi >  vvi;


void solve(){
    int n, p, ans = 0;
    cin >> n >> p;
    vi con(n + 6, 0);
    vector < pii > vec;
    int a[n + 6];
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        vec.pb({a[i], i});
    }
    sort(all(vec));
    for(auto el : vec){
        int x = el.F, pos = el.S;
        if(x >= p){
            break;
        }
        while(pos > 1){
            if(a[pos - 1] % x != 0){
                break;
            }
            if(con[pos - 1]){
                break;
            }
            con[pos - 1] = 1;
            pos--;
            ans += x;
        }
        x = el.F, pos = el.S;
        while(pos < n){
            if(a[pos + 1] % x != 0){
                break;
            }
            if(con[pos]){
                break;
            }
            con[pos] = 1;
            ans += x;
            pos++;
        }
    }
    for(int i = 1; i < n; i++){
        if(!con[i]){
            ans += p;
        }
    }
    cout << ans;
}

signed main() {
    int t = 1;
    cin >> t;
    while (t--) {
        solve();
        cout << "\n";
    }
}

