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

int main() {
  
  ios::sync_with_stdio(false);
  cin.tie(0);
  
  int n,p;
  long long k;
  cin >> n >> k >> p;
  vector<int> a(n);
  vector<int> b(n);
  for (int i=0;i<n;i++) {
    cin >> a[i];
  }
  for (int i=0;i<n;i++) {
    cin >> b[i];
  }
  sort(a.begin(),a.end());
  sort(b.begin(),b.end());
  int i = 0;
  int j = n-1;
  long long pcnt = 0;
  while (i < n && j >= 0) {
    if (a[i]+b[j] < p) {
      pcnt += j+1;
      i++;
    }
    else {
      j--;
    }
  }
  int l = 0;
  int h = p-1;
  int las = h;
  while (l <= h) {
    int now = (l+h)/2;
    i = 0;
    j = n-1;
    long long ncnt = 0;
    while (i < n && j >= 0) {
      if (a[i]+b[j] <= now) {
        ncnt += j+1;
        i++;
      }
      else {
        j--;
      }
    }
    i = 0;
    j = n-1;
    long long npcnt = 0;
    while (i < n && j >= 0) {
      if (a[i]+b[j] <= now+p) {
        ncnt += j+1;
        i++;
      }
      else {
        j--;
      }
    }
    long long cnt = npcnt-pcnt+ncnt;
    //cout << now << ' ' << cnt << endl;
    if (cnt >= k) {
      las = now;
      h = now-1;
    }
    else {
      l = now+1;
    }
  }
  cout << las << endl;
}