#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef set<int> si;
const int inf = 1e9;
const int mod = 1e9+7;

ll n, m, a[100000], k;
bool ok(int idx){
  ll l = -1, r = n, count = 0;
  ll p = a[idx] + k;
  while(count < m){
    r--;
    if(r == idx)r--;
    while(true){
      l++;
      if(l >= r)return true;
      if(l == idx || a[l] + a[r] <= p)continue;
      count++;
      break;
    }
  }
  return false;
}
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  int aa;
  cin >> n >> m >> k;
  n--;
  FOR(i, 0, n) cin >> a[i];
  sort(a, a+n);
  ll mi = -1, ma = n-1;
  while(ma - mi > 1){
    ll mid = (ma + mi)/2;
    if(ok(mid)){
      ma = mid;
    }else{
      mi = mid;
    }
  }
  cout << (ok(ma) ? a[ma] : -1) << "\n";
}