#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int Mod=1e9+7;
const ll INF = 10000000000000;
const int N = 1e6+7;
 
bool f(ll mid ,vector<ll>&a,ll x){
 ll check=0;
 for(int i=0;i<a.size() && a[i]<mid;i++)
    check+=mid-a[i];
  return check<=x;
}
 
void solve() {
  ll n,x;
  cin >> n >> x;
  vector<ll> a(n);
  sort(a.begin(),a.end());
  for(ll i=0;i<n;i++) cin >> a[i];
  ll l=1,r=1e9+7;
  ll ans = 1;
  while(l<=r){
    ll m = (l+r)/2;   
    if(f(m,a,x)){
      ans=m;
      l=m+1;
    }
    else r=m-1;
  }
  cout << ans << '\n';
}       
 
int main(){ 
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
 
    int t;
    cin >> t;
    while (t--) solve();
 
 
    return 0;
}
 

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5
7 9
3 1 2 4 6 2 5
3 10
1 1 1
4 1
1 4 3 4
6 1984
2 6 5 9 1 8
1 1000000000
1