import java.util.Arrays; public class Main { private static void solve() { int n = ni(); int m = ni(); int[] v = na(n); int[] r = na(m); long a = ni(); long b = ni(); int mod = (int) 1e9 + 7; int max1 = Arrays.stream(v).sum(); int max2 = Arrays.stream(r).sum(); long[] dp1 = new long[max1 + 1]; long[] dp2 = new long[max2 + 1]; dp1[0] = 1; dp2[0] = 1; for (int i = 0; i < n; i++) { for (int j = max1; j >= v[i]; j--) { dp1[j] += dp1[j - v[i]]; dp1[j] %= mod; } } for (int i = 0; i < m; i++) { for (int j = max2; j >= r[i]; j--) { dp2[j] += dp2[j - r[i]]; dp2[j] %= mod; } } long[] sum = new long[max1 + 2]; for (int i = 0; i <= max1; i++) { sum[i + 1] = sum[i] + dp1[i]; } long ret = 0; for (int i = 1; i <= max2; i++) { int from = (int)Math.min(max1 + 1, i * a); int to = (int)Math.min(max1 + 1, i * b + 1); ret += dp2[i] * (sum[to] - sum[from]) % mod; ret %= mod; } System.out.println(ret); } public static void main(String[] args) { new Thread(null, new Runnable() { @Override public void run() { long start = System.currentTimeMillis(); String debug = args.length > 0 ? args[0] : null; if (debug != null) { try { is = java.nio.file.Files.newInputStream(java.nio.file.Paths.get(debug)); } catch (Exception e) { throw new RuntimeException(e); } } reader = new java.io.BufferedReader(new java.io.InputStreamReader(is), 32768); solve(); out.flush(); tr((System.currentTimeMillis() - start) + "ms"); } }, "", 64000000).start(); } private static java.io.InputStream is = System.in; private static java.io.PrintWriter out = new java.io.PrintWriter(System.out); private static java.util.StringTokenizer tokenizer = null; private static java.io.BufferedReader reader; public static String next() { while (tokenizer == null || !tokenizer.hasMoreTokens()) { try { tokenizer = new java.util.StringTokenizer(reader.readLine()); } catch (Exception e) { throw new RuntimeException(e); } } return tokenizer.nextToken(); } private static double nd() { return Double.parseDouble(next()); } private static long nl() { return Long.parseLong(next()); } private static int[] na(int n) { int[] a = new int[n]; for (int i = 0; i < n; i++) a[i] = ni(); return a; } private static char[] ns() { return next().toCharArray(); } private static long[] nal(int n) { long[] a = new long[n]; for (int i = 0; i < n; i++) a[i] = nl(); return a; } private static int[][] ntable(int n, int m) { int[][] table = new int[n][m]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[i][j] = ni(); } } return table; } private static int[][] nlist(int n, int m) { int[][] table = new int[m][n]; for (int i = 0; i < n; i++) { for (int j = 0; j < m; j++) { table[j][i] = ni(); } } return table; } private static int ni() { return Integer.parseInt(next()); } private static void tr(Object... o) { if (is != System.in) System.out.println(java.util.Arrays.deepToString(o)); } }