package _1163; import java.io.BufferedReader; import java.io.EOFException; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import java.io.UncheckedIOException; import java.lang.reflect.Array; import java.util.ArrayDeque; import java.util.Arrays; import java.util.Deque; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Objects; import java.util.regex.Pattern; import java.util.stream.Collectors; import java.util.stream.IntStream; public class Main { public void exec() { int n = stdin.nextInt(); long x = stdin.nextLong(); long[] a = stdin.nextLongArray(n); long[] b = stdin.nextLongArray(n); for (int i = 0; i < n; i++) { a[i] -= x; } if (Arrays.stream(a).sum() >= 0) { stdout.println(0); return; } if (Arrays.stream(a).allMatch(v -> v < 0)) { stdout.println(-1); return; } List> dp = IntStream.range(0, n+1).mapToObj(unused -> new HashMap()).collect(Collectors.toList()); dp.get(0).put(Arrays.stream(a).sum(), 0L); for (int i = 0; i < n; i++) { for (Long k : dp.get(i).keySet()) { update(dp.get(i + 1), k, dp.get(i).get(k)); update(dp.get(i + 1), k-a[i], dp.get(i).get(k)+b[i]); } } long ans = dp.get(n).entrySet().stream().filter(e -> e.getKey() >= 0).mapToLong(Entry::getValue).min().getAsLong(); stdout.println(ans); } public void update(Map d, Long key, Long value) { if (d.containsKey(key)) { if (d.get(key).compareTo(value) > 0) { d.put(key, value); } } else { d.put(key, value); } } private static final Stdin stdin = new Stdin(); private static final Stdout stdout = new Stdout(); public static void main(String[] args) { try { new Main().exec(); } finally { stdout.flush(); } } public static class Stdin { private BufferedReader stdin; private Deque tokens; private Pattern delim; public Stdin() { stdin = new BufferedReader(new InputStreamReader(System.in)); tokens = new ArrayDeque<>(); delim = Pattern.compile(" "); } public String nextString() { try { if (tokens.isEmpty()) { String line = stdin.readLine(); if (line == null) { throw new UncheckedIOException(new EOFException()); } delim.splitAsStream(line).forEach(tokens::addLast); } return tokens.pollFirst(); } catch (IOException e) { throw new UncheckedIOException(e); } } public int nextInt() { return Integer.parseInt(nextString()); } public double nextDouble() { return Double.parseDouble(nextString()); } public long nextLong() { return Long.parseLong(nextString()); } public String[] nextStringArray(int n) { String[] a = new String[n]; for (int i = 0; i < n; i++) a[i] = nextString(); return a; } public int[] nextIntArray(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = nextInt(); return a; } public double[] nextDoubleArray(int n) { double[] a = new double[n]; for (int i = 0; i < n; i++) a[i] = nextDouble(); return a; } public long[] nextLongArray(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nextLong(); return a; } } public static class Stdout { private PrintWriter stdout; public Stdout() { stdout = new PrintWriter(System.out, false); } public void printf(String format, Object ... args) { String line = String.format(format, args); if (line.endsWith(System.lineSeparator())) { stdout.print(line); } else { stdout.println(line); } } public void println(Object ... objs) { String line = Arrays.stream(objs).map(Objects::toString).collect(Collectors.joining(" ")); stdout.println(line); } public void debug(Object ... objs) { String line = Arrays.stream(objs).map(this::deepToString).collect(Collectors.joining(" ")); stdout.printf("DEBUG: %s%n", line); } private String deepToString(Object o) { if (o == null) { return "null"; } // 配列の場合 if (o.getClass().isArray()) { int len = Array.getLength(o); String[] tokens = new String[len]; for (int i = 0; i < len; i++) { tokens[i] = deepToString(Array.get(o, i)); } return "{" + String.join(",", tokens) + "}"; } return Objects.toString(o); } private void flush() { stdout.flush(); } } }