#include<bits/stdc++.h>
#define x first
#define y second
#define PB push_back
#define mst(x,a) memset(x,a,sizeof(x))
#define all(a) begin(a),end(a)
#define rep(x,l,u) for(ll x=l;x<u;x++)
#define rrep(x,l,u) for(ll x=l;x>=u;x--)
#define IOS ios::sync_with_stdio(false);cin.tie(0);
using namespace std;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef pair<long,long> PLL;
typedef pair<char,char> PCC;
typedef long long ll;
const int N=2*1e5+10;
const int M=1e6+10;
const int INF=0x3f3f3f3f;
const int MOD=1e9+7;
ll a[N],f[N];
void solve(){
ll n,p,k;cin>>n>>p>>k;
rep(i,1,n+1) cin>>a[i];
sort(a+1,a+n+1);
ll ans=0;
rep(i,1,n+1){
if(i>=k){
f[i]=min(f[i-1],f[i-k])+a[i];
}else f[i]=f[i-1]+a[i];
if(f[i]<=p) ans=max(ans,i);
}
cout<<ans<<endl;
}
int main(){
IOS;
int t;cin>>t;
while(t--){
solve();
}
return 0;
}