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

//  The 2024 ICPC Kunming Invitational Contest

//  向上取整的代价不同.

void sol(){
    int n, k;
    std::cin>>n>>k;

    std::vector<int>a(n);
    for(int i = 0;i < n;i++){
        std::cin>>a[i];
    }

    int m; 
    std::cin>>m;

    int ans = 0;
    std::vector<std::array<int, 2>>V(n);
    for(int i = 0;i < n;i++){
        int res = (a[i] + k - 1) / k * k - a[i];
        V[i] = {res, a[i]};
    }
    std::sort(V.begin(), V.end());

    for(int i = 0;i < n;i++){
        auto [need, vi] = V[i];
        if(m > need){
            m = m - need;
            ans += (vi + need) / k;
        }else{
            ans += (vi + m) / k;
            m = 0;
        }
    }

    ans += m / k;
    std::cout<<ans<<"\n";
}

signed main(){
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t = 1; std::cin>>t;
    while(t--) sol();  
    return 0;
}