#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int k; ll n; cin >> k >> n;
  vector<ll> a(k * 2, -LINF), b(k);
  REP(i, k) cin >> a[i];
  REP(i, k) cin >> b[i];
  FOR(i, k, k * 2) REP(j, k) chmax(a[i], min(a[i - k + j], b[j]));
  if (n < k * 2) {
    cout << a[n] << '\n';
    return 0;
  }
  ll lb = min(*min_element(ALL(a)), *min_element(ALL(b))), ub = min(*max_element(ALL(a)), *max_element(ALL(b))) + 1;
  while (ub - lb > 1) {
    ll x = (lb + ub) / 2;
    vector<int> t;
    for (int i = k - 1; i >= 0; --i) {
      if (b[i] >= x) t.emplace_back(k - i);
    }
    if (t.empty()) {
      ub = x;
      continue;
    }
    int t0 = t.front();
    vector<ll> dist(t0, LINF);
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> que;
    FOR(i, k, k * 2) {
      if (a[i] >= x && dist[i % t0] == LINF) {
        dist[i % t0] = i;
        que.emplace(i, i % t0);
      }
    }
    while (!que.empty()) {
      auto [cost, ver] = que.top(); que.pop();
      for (int ti : t) {
        if (ll nx = cost + ti; nx < dist[(ver + ti) % t0]) {
          dist[(ver + ti) % t0] = nx;
          que.emplace(nx, (ver + ti) % t0);
        }
      }
    }
    (dist[n % t0] <= n ? lb : ub) = x;
  }
  cout << lb << '\n';
  return 0;
}