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

ll solve() {
    ll N, K, P;
    cin >> N >> K >> P;
    vector<ll> A(N), 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());

    auto get_le = [&](ll x) -> ll {
        ll s = 0;
        for ( int i = 0; i < N; i++ ) {
            s += upper_bound(B.begin(), B.end(), x-A[i]) - lower_bound(B.begin(), B.end(), -A[i]);
            s += upper_bound(B.begin(), B.end(), P+x-A[i]) - lower_bound(B.begin(), B.end(), P-A[i]);
        }
        return s;
    };
    
    // 単調非減少関数f(x), x:定義域[l,r), 戻り値は [l,r]
    // y <= f(x) となる最小のx
    auto lower_bound_f = [](ll l, ll r, ll y, auto f) -> ll {
        l--;
        while ( r-l > 1 ) {
            ll m = l + (r-l)/2;
            ll fx = f(m);
            if ( y <= fx ) r = m;
            else l = m;
        }
        return r;
    };

    ll ans = lower_bound_f(0,P,K,get_le);
    return ans;
}

int main() {
    auto ans = solve();
    cout << ans << "\n";
    return 0;
}