#include <bits/stdc++.h>

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<int64_t> 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 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]; });
	
	std::set<int> start;
	std::set<int> move;
	for (auto i : index) {
		if (i < k) start.insert(i);
		else move.insert(i - k + 1);
		
		if (!move.size()) continue;
		
		
		int g = 0;
		for (auto j : move) g = gcd(g, j);
		
		// std::cerr << "added " << i << std::endl;
		bool ok = false;
		if (n > k * k) {
			assert(0);
			for (auto i : start) if ((n - i) % g == 0) ok = true;
		} else {
			bool dp[k * k + 1];
			memset(dp, 0, sizeof(dp));
			for (auto i : start) dp[i] = true;
			for (int i = 0; i < k * k; i++) {
				if (!dp[i]) continue;
				for (auto j : move) if (i + j <= k * k) dp[i + j] = true;
			}
			if (dp[n]) ok = true;
		}
		if (ok) {
			printf("%" PRId64 "\n", a[i]);
			return 0;
		}
	}
	assert(0);
	
	return 0;
}