import static java.lang.Math.*;
import static java.math.BigInteger.*;
import static java.util.Arrays.*;
import static java.util.Collections.*;
import java.math.*;
import java.util.*;
import java.io.*;

public class Main {
	public static void main(String[] args) { new Main().run(); }
	Scanner in = new Scanner(System.in);
	void _out(Object...os) { System.out.println(deepToString(os)); }
	void _err(Object...os) { System.err.println(deepToString(os)); }
	
	void run() {
		long INF = 1_000_000_000_000_000_000L + 1;
		for (; in.hasNext(); ) {
			int n = in.nextInt();
			long m = in.nextLong();
			int[] as = new int[n];
			for (int i = 0; i < n; ++i) {
				as[i] = in.nextInt();
			}
			long[] ks = new long[n];
			for (int i = 0; i < n; ++i) {
				ks[i] = in.nextLong();
			}
			int lim = as[n - 1] << 1;
			long[] dp;
			for (; ; lim <<= 1) {
				dp = new long[lim + 1];
				for (int x = 0; x <= lim; ++x) {
					dp[x] = INF;
				}
				dp[0] = 0;
				for (int i = 0; i < n; ++i) {
					for (int x = as[i]; x <= lim; ++x) {
						if (dp[x] > dp[x - as[i]] + 1) {
							dp[x] = dp[x - as[i]] + 1;
						}
					}
				}
				boolean ok = true;
				for (int x = lim - as[n - 1]; x <= lim; ++x) {
					ok &= (dp[x] >= INF || dp[x] == dp[x - as[n - 1]] + 1);
				}
				if (ok) {
					break;
				}
			}
			_err(lim);
			long target = -m;
			for (int i = 0; i < n; ++i) {
				target += as[i] * ks[i];
			}
			long ans;
			if (target < 0) {
				ans = INF;
			} else if (target <= lim) {
				ans = dp[(int)target];
			} else {
				long greed = ((target - lim) + as[n - 1] - 1) / as[n - 1];
				ans = greed + dp[(int)(target - as[n - 1] * greed)];
			}
			System.out.println((ans >= INF) ? -1 : ans);
		}
	}
}