#include <bits/stdc++.h>
#define N 100005
using namespace std;
int T;
int n, k, k2, ans;
int a[N];
int p, q, lst;
void solve() {
    ans = 0;
    scanf("%d%d", &n, &k);
    for (int i = 0; i < n; ++i) {
        scanf("%d", &a[i]);
    }
    sort(a, a + n);
    p = q = 0;
    lst = -2000000001;
    while (p < n && q < n) {
        while (a[q] == a[p]) {
            ++q;
        }
        int len = q - p;
        for (int i = max(lst + 1, a[p] - k); i <= a[p] + k && len; ++i, --len) {
            ++ans;
            lst = i;
            //printf("%d\n", i);
        }
        p = q;
    }
    printf("%d\n", ans);
}
int main() {
    scanf("%d", &T);
    while (T--) {
        solve();
    }
}