#include <algorithm>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
#define setIO(x) freopen(x".in", "r", stdin), freopen(x".out", "w", stdout)
#define closefile fclose(stdin), fclose(stdout)
#define m_p make_pair
#define sz(x) (int)x.size()
#define see(x) cerr << x << " "
#define seeln(x) cerr << x << endl
#define out(x) cerr << #x << " = " << x << " "
#define outln(x) cerr << #x << " = " << x << endl
#define outarr(x, l, r) {cerr << #x"[" << l << " ~ " << r << "] = "; for (int _i = l; _i <= r; ++_i) cerr << x[_i] << " "; cerr << endl;}
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
template <class T> bool checkmax(T &a, T b){return a < b ? a = b, 1 : 0;}
template <class T> bool checkmin(T &a, T b){return b < a ? a = b, 1 : 0;}
const int N = 100005;
int n, k;
ll a[N];

void init()
{
    scanf("%d%d", &n, &k);
    for (int i = 1; i <= n; ++i) scanf("%lld", &a[i]);
    sort(a + 1, a + n + 1);
}

void solve()
{
    ll v = -1000000000, ans = 0;
    for (int i = 1; i <= n; )
    {
        int j = i;
        while (j < n && a[j + 1] == a[i]) ++j;
        ll lft = max(v, a[i]);
        ll len = j - i + 1;
        if (lft <= a[i] + k + k)
        {
            ll t = min(a[i] + k + k - lft + 1, len);
            v = lft + t;
            ans += t;
        }
        i = j + 1;
    }
    printf("%lld\n", ans);
}

int main()
{
    int t; scanf("%d", &t); while (t--)
    {
        init();
        solve();
    }
    return 0;
}