#ifdef __LOCAL
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int,int>;
using PIL = pair<int,ll>;
using PLI = pair<ll,int>;
using PLL = pair<ll,ll>;

template<class T> bool chmin(T &a, T b) {if(a>b){a=b;return 1;}return 0;}
template<class T> bool chmax(T &a, T b) {if(a<b){a=b;return 1;}return 0;}
template<class T> void show_vec(T v) {for (int i=0;i<v.size();i++) cout<<v[i]<<endl;}
template<class T> void show_pair(T p) {cout<<p.first<<" "<<p.second<<endl;}
template<class T> bool judge_digit(T bit,T i) {return (((bit&(1LL<<i))!=0)?1:0);}
#define REP(i,n) for(int i=0;i<int(n);i++)
#define ROUNDUP(a,b) (((a)+(b)-1)/(b))
#define YESNO(T) cout<<(T?"YES":"NO")<<endl
#define yesno(T) cout<<(T?"yes":"no")<<endl
#define YesNo(T) cout<<(T?"Yes":"No")<<endl

const int INFint = 1 << 29;
const ll INF = 1LL << 60;
const ll MOD = 1000000007LL;
const double pi = 3.14159265358979;
const vector<int> h_idx4 = {-1, 0,0,1};
const vector<int> w_idx4 = { 0,-1,1,0};
const vector<int> h_idx8 = {-1,-1,-1, 0,0, 1,1,1};
const vector<int> w_idx8 = {-1, 0, 1,-1,1,-1,0,1};

ll n,k,p;
vector<ll> a,b;

bool under_num_isOK(int index, ll key, vector<ll> &vec){
    if (vec[index] <= key) return true;
    else return false;
}

// 二分探索をする
ll under_num(ll key,vector<ll> &vec){
    int ng = vec.size();
    int ok = -1;

    while (abs(ok - ng) > 1){
        int mid = (ok + ng) / 2;

        if (under_num_isOK(mid, key, vec)) ok = mid;
        else ng = mid;
    }

    return ll(ok + 1);
}

bool Binary_Search_isOK(ll x){
    ll cnt = 0;
    for (int i = 0; i < n; i++){
        if (x >= b[i]){
            if (x - b[i] >= p - b[i]) cnt += n;
            else{
                cnt += under_num(x - b[i],a);
                cnt += (n - under_num(p - b[i] - 1,a));
            }
        }
        else{
            cnt += under_num(p + x - b[i],a) - under_num(p - b[i] - 1,a);
        }
    }

    // cout << x << " " << cnt << endl;

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

// 二分探索をする
ll Binary_Search(){
    ll ng = -1;
    ll ok = p;

    while (abs(ok - ng) > 1){
        ll mid = (ok + ng) / 2;

        if (Binary_Search_isOK(mid)) ok = mid;
        else ng = mid;
    }

    return ok;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    cin >> n >> k >> p;

    a.resize(n);
    for (int i = 0; i < n; i++){
        cin >> a[i];
    }
    b.resize(n);
    for (int i = 0; i < n; i++){
        cin >> b[i];
    }

    sort(a.begin(), a.end());
    sort(b.begin(), b.end());

    cout << Binary_Search() << endl;

}