// #define _GLIBCXX_DEBUG
#include<bits/stdc++.h>
#include <atcoder/all>
#define rep(i, n) for (long long i = 0; i < (n); i++)
#define rep1(i, n) for(long long i = 1; i <= (n); i++)
#define all(v) v.begin(),v.end()
#define decimal(n) cout << fixed << setprecision(n);
using namespace std; 
using namespace atcoder;
using ll = long long; using vl = vector<ll>; using P = pair<ll,ll>;
using vvl = vector<vl>; using vc = vector<char>; using vvc = vector<vc>;
// using mint = modint998244353;
using mint = modint1000000007;
const ll MOD = 1000000007;
const ll MAX = 2000100; const ll inf = 3e18; const long double pi = acos(-1);
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
ll lcm(ll a,ll b){ return (a*b) / gcd(a,b); }

ll n,k,p;
vl a,b;

//ここに適切な判断条件を書く
bool isOK(ll index){
  ll cnt = 0;

  rep(i, n){
    cnt += upper_bound(all(b), index - a[i]) - b.begin();
    cnt += upper_bound(all(b), p + index - a[i]) - lower_bound(all(b), p - a[i]);
  }

  if(cnt >= k) return true;
  return false;
}

//臨機応変に引数を書き換える
ll binary_search() {
//どっちがngか，どっちがokか認識しているか？
//探索範囲の上限，下限をしっかり理解しているか？
   ll ng = -1;
   ll ok = p - 1;
   while (abs(ok - ng) > 1) {
      ll mid = (ok + ng) / 2;
      if (isOK(mid)) ok = mid;
      else ng = mid;
   }
   return ok;
}

int main(){
  cin >> n >> k >> p; a.resize(n); b.resize(n);
  rep(i, n) cin >> a[i]; rep(i, n) cin >> b[i];

  sort(all(a)); sort(all(b));
  cout << binary_search() << endl;
}