#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 5;
long long a[N];
map<long long, int> mp;
map<long long, int> vis;
int main()
{
    int t;
    scanf("%d", &t);
    while (t--)
    {
        mp.clear();
        vis.clear();
        long long n, k;
        scanf("%lld %lld", &n, &k);
        for (int i = 1; i <= n; i++)
        {
            scanf("%d", &a[i]);
            mp[a[i]]++;
        }
        long long pre = -1e18, ans = 0;
        for (auto it : mp)
        {
            long long val = it.first;
            long long num = it.second;
            long long L = max(pre + 1, val - k);
            long long R = min(L + num - 1, val + k);
            ans += R - L + 1;
            pre = R;
        }
        cout << ans << endl;
        // cout << '\t' << ans << endl;
    }

    return 0;
}
/*
1
6 1
1 2 2 2 2 3

0 1 2 3 3 4
*/