#include int ri() { int n; scanf("%d", &n); return n; } int gcd(int a, int b) { while (a && b) { if (a > b) a %= b; else b %= a; } return a + b; } int main() { int k = ri(); int64_t n; std::cin >> n; std::vector a(k + k); for (auto &i : a) std::cin >> i; std::reverse(a.begin() + k, a.end()); if (n < k) { printf("%" PRId64 "\n", a[n]); return 0; } int threashold = k * k + k; int index[k + k]; std::iota(index, index + k + k, 0); std::sort(index, index + k + k, [&] (int i, int j) { return a[i] > a[j]; }); int l = 0; int r = k + k; while (r - l > 1) { int m = l + ((r - l) >> 1); std::vector start; std::vector move; for (int i = 0; i < m; i++) { if (index[i] < k) start.push_back(index[i]); else move.push_back(index[i] - k + 1); } bool ok = false; if (!move.size()) ok = false; else if (n > threashold) { int g = 0; for (auto j : move) g = gcd(g, j); for (auto i : start) for (auto j : move) if (i + j >= k && (n - i - j) % g == 0) ok = true; } else { bool dp[threashold + 1]; memset(dp, 0, sizeof(dp)); for (auto i : start) dp[i] = true; for (int i = 0; i < threashold; i++) { if (!dp[i]) continue; for (auto j : move) if (i + j <= threashold && i + j >= k) dp[i + j] = true; } if (dp[n]) ok = true; } if (ok) r = m; else l = m; } printf("%" PRId64 "\n", a[index[l]]); return 0; }