using System; namespace No93 { public class Program { static void Main() { var N = int.Parse(Console.ReadLine()); var dp = new ModInt[N + 2, N + 2, 2, 2]; dp[1, 0, 0, 0] = 1; dp[2, 0, 0, 0] = 2; for (var n = 3; n <= N; n++) for (var k = 0; k <= n - 2; k++) { dp[n, k + 1, 1, 0] += dp[n - 1, k, 0, 0] * 2; dp[n, k + 1, 1, 0] += dp[n - 1, k, 0, 1] * 1; dp[n, k + 1, 1, 1] += dp[n - 1, k, 1, 0] * 2; dp[n, k + 1, 1, 1] += dp[n - 1, k, 1, 1] * 1; dp[n, k, 0, 0] += dp[n - 1, k, 0, 0] * (n - k - 2); dp[n, k, 0, 0] += dp[n - 1, k, 0, 1] * (n - k - 1); dp[n, k, 0, 1] += dp[n - 1, k, 1, 0] * (n - k - 2); dp[n, k, 0, 1] += dp[n - 1, k, 1, 1] * (n - k - 1); dp[n, k, 1, 0] += dp[n - 1, k, 0, 1] * 1; dp[n, k, 1, 1] += dp[n - 1, k, 1, 1] * 1; if (k <= 0) continue; dp[n, k - 1, 0, 0] += dp[n - 1, k, 0, 0] * k; dp[n, k - 1, 0, 0] += dp[n - 1, k, 1, 0] * 1; dp[n, k - 1, 0, 0] += dp[n - 1, k, 0, 1] * (k - 1); dp[n, k - 1, 0, 0] += dp[n - 1, k, 1, 1] * 1; dp[n, k - 1, 0, 1] += dp[n - 1, k, 1, 0] * (k - 1); dp[n, k - 1, 0, 1] += dp[n - 1, k, 1, 1] * (k - 2); } Console.WriteLine(dp[N, 0, 0, 0]); } } public struct ModInt { public static int Mod = 1000000007; readonly long value; public int Value { get { return (int)value; } } public ModInt Inverse { get { return GetInverse(); } } public ModInt(long value) { value %= Mod; this.value = value < 0 ? value + Mod : value; } ModInt GetInverse() { if (value == 0) throw new InvalidOperationException("value must NOT equal 0"); return Pow(Mod - 2); } public ModInt Square() { return this * this; } public ModInt Pow(long exp) { if (exp == 0) return 1; if (exp % 2 == 0) return Pow(exp / 2).Square(); return this * Pow(exp - 1); } public static ModInt Parse(string str) { return long.Parse(str); } public static implicit operator ModInt(long value) { return new ModInt(value); } public static ModInt operator +(ModInt left, ModInt right) { return left.value + right.value; } public static ModInt operator -(ModInt left, ModInt right) { return left.value - right.value; } public static ModInt operator *(ModInt left, ModInt right) { return left.value * right.value; } public static ModInt operator /(ModInt left, ModInt right) { return left * right.Inverse; } public override bool Equals(object obj) { if (!(obj is ModInt)) return false; return value == ((ModInt)obj).value; } public override int GetHashCode() { return value.GetHashCode(); } public override string ToString() { return value.ToString(); } } }