#include #include #include using namespace std; const int MOD = (int)1e9 + 7; //--------------------------------------------------------------- template struct ModInt { int x; explicit operator bool() const { return !!x; } ModInt(int v = 0) : x(v % MOD) { if (x < 0) x += MOD; } ModInt(long long v) : x(v % MOD) { if (x < 0) x += MOD; } ModInt &operator+=(const ModInt &r) { if ((x += r.x) >= MOD) x -= MOD; return *this; } ModInt &operator-=(const ModInt &r) { if ((x += MOD - r.x) >= MOD) x -= MOD; return *this; } ModInt &operator*=(const ModInt &r) { x = 1LL * x * r.x % MOD; return *this; } ModInt &operator/=(const ModInt &r) { return *this *= r.inv(); } ModInt operator-() const { return x ? ModInt(MOD - x) : ModInt(x); } ModInt operator+(const ModInt &r) const { return ModInt(*this) += r; } ModInt operator-(const ModInt &r) const { return ModInt(*this) -= r; } ModInt operator*(const ModInt &r) const { return ModInt(*this) *= r; } ModInt operator/(const ModInt &r) const { return ModInt(*this) /= r; } ModInt inv() const { long long a = x, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } // x.pow(MOD-2) ModInt pow(long long k) const { ModInt r(1), a(x); while (k) { if (k & 1) r *= a; a *= a; k >>= 1; } return r; } bool operator==(const ModInt r) const { return x == r.x; } bool operator!=(const ModInt r) const { return x != r.x; } bool operator< (const ModInt r) const { return x < r.x; } friend ostream& operator<<(ostream &os, const ModInt& a) { return os << a.x; } friend istream& operator>>(istream &is, ModInt& a) { return is >> a.x; } }; template struct Comb { vector _fac, _ifac, _inv; Comb() : _fac(SZ + 1), _ifac(SZ + 1), _inv(SZ + 1) { _fac[0] = _ifac[SZ] = _inv[0] = 1; for (int i = 1; i <= SZ; i++) _fac[i] = _fac[i - 1] * i; _ifac[SZ] /= _fac[SZ]; for (int i = SZ - 1; i >= 0; i--) _ifac[i] = _ifac[i + 1] * (i + 1); for (int i = 1; i <= SZ; i++) _inv[i] = _ifac[i] * _fac[i - 1]; } T inv(int n) { return n < 0 ? T(0) : _inv[n]; } T fac(int n) { return n < 0 ? T(0) : _fac[n]; } T ifac(int n) { return n < 0 ? T(0) : _ifac[n]; } T P(int a, int b) { return (b < 0 || a < b) ? T(0) : _fac[a] * _ifac[a - b]; } T C(int a, int b) { return b < 0 ? T(0) : P(a, b) * _ifac[b]; } T H(int n, int k) { if (n < 0 || k < 0) return T(0); return k == 0 ? T(1) : C(n + k - 1, k); } T S(int n, int k) { T r = 0; for (int i = 0; i <= k; i++) { T t = C(k, i) * T(i).pow(n); r += ((k - i) & 1 ? -t : t); } return r * _ifac[k]; } T B(int n, int k) { if (n == 0) return T(1); T r = 0; k = min(k, n); vector dp(k + 1); dp[0] = T(1); for (int i = 1; i <= k; i++) dp[i] = dp[i - 1] + (i & 1 ? -_ifac[i] : _ifac[i]); for (int i = 1; i <= k; i++) r += T(i).pow(n) * _ifac[i] * dp[k - i]; return r; } }; typedef ModInt mint; //--------------------------------------------------------------- template vector> stirling2_table(int ma) { vector> dp(ma + 1, vector(ma + 1, 0)); dp[0][0] = 1; for (int i = 1; i <= ma; i++) { for (int j = 1; j <= i; j++) { dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j] * j; } } return dp; } int main() { Comb com; int n; cin >> n; mint ans = 0; auto dp = stirling2_table(n); for (int x = 0; x <= n; x++) for (int y = 0; y <= n; y++) { ans += com.C(n, x) * dp[x][y] * mint(y * (y - 1)).pow(n - x); } cout << ans << endl; return 0; }