#include <iostream>
#include <unordered_map>
#include <unordered_set>
#include <set>
#include <vector>
#include <numeric>
#include <algorithm>
#include <queue>
#include <string>
#include <random>
#include <array>
#include <climits>
#include <map>
#include <cassert>
#include <stack>
#include <iomanip>
#include <cfloat>
#include <bitset>
#include <fstream>
#include <chrono>

int main() {
	constexpr int MAX_K = 100000;
	constexpr int SEGMENT = 100;
	int n, k; std::cin >> n >> k;
	std::vector<int> number(n);
	for (auto& a : number) {
		std::cin >> a;
	}
	std::vector<std::bitset<MAX_K + 1>> forward_memo((n + SEGMENT - 1) / SEGMENT);
	std::bitset<MAX_K + 1> forward; forward.set(0, true);
	for (auto i = 0; i < n; ++i) {
		if (i % SEGMENT == 0) {
			forward_memo[i / SEGMENT] = forward;
		}
		forward |= forward << number[i];
	}
	if (forward.test(k)) {
		int result{ 0 };
		std::bitset<MAX_K + 1> backward; backward.set(k, true);
		std::vector<std::bitset<MAX_K + 1>> forward_cache; forward_cache.reserve(SEGMENT);
		for (int i = n - 1; i >= 0; --i) {
			if (forward_cache.empty()) {
				const auto from = i / SEGMENT * SEGMENT;
				const auto until = std::min(n, from + SEGMENT);
				forward_cache.push_back(forward_memo[i / SEGMENT]);
				for (auto j = from + 1; j < until; ++j) {
					forward_cache.push_back(forward_cache.back() | (forward_cache.back() << number[j - 1]));
				}
			}
			const auto a = number[i];
			if ((backward & forward_cache.back()).none()) {
				result += 1;
			}
			backward |= backward >> a;
			forward_cache.pop_back();
		}
		std::cout << result << '\n';
	}
	else {
		std::cout << "-1\n";
	}
}