#include #include #include #include using namespace std; // modint template struct Fp { long long val; constexpr Fp(long long v = 0) noexcept : val(v % MOD) { if (val < 0) val += MOD; } constexpr int getmod() { return MOD; } constexpr Fp operator - () const noexcept { return val ? MOD - val : 0; } constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; } constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; } constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; } constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; } constexpr Fp& operator += (const Fp& r) noexcept { val += r.val; if (val >= MOD) val -= MOD; return *this; } constexpr Fp& operator -= (const Fp& r) noexcept { val -= r.val; if (val < 0) val += MOD; return *this; } constexpr Fp& operator *= (const Fp& r) noexcept { val = val * r.val % MOD; return *this; } constexpr Fp& operator /= (const Fp& r) noexcept { long long a = r.val, 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); } val = val * u % MOD; if (val < 0) val += MOD; return *this; } constexpr bool operator == (const Fp& r) const noexcept { return this->val == r.val; } constexpr bool operator != (const Fp& r) const noexcept { return this->val != r.val; } friend constexpr ostream& operator << (ostream &os, const Fp& x) noexcept { return os << x.val; } friend constexpr istream& operator >> (istream &is, Fp& x) noexcept { return is >> x.val; } friend constexpr Fp modpow(const Fp &a, long long n) noexcept { if (n == 0) return 1; auto t = modpow(a, n / 2); t = t * t; if (n & 1) t = t * a; return t; } }; // 二項係数ライブラリ template struct BiCoef { vector fact_, inv_, finv_; constexpr BiCoef(int n) noexcept : fact_(n, 1), inv_(n, 1), finv_(n, 1) { int MOD = fact_[0].getmod(); for(int i = 2; i < n; i++){ fact_[i] = fact_[i-1] * i; inv_[i] = -inv_[MOD%i] * (MOD/i); finv_[i] = finv_[i-1] * inv_[i]; } } constexpr T com(int n, int k) const noexcept { if (n < k || n < 0 || k < 0) return 0; return fact_[n] * finv_[k] * finv_[n-k]; } constexpr T fact(int n) const noexcept { if (n < 0) return 0; return fact_[n]; } constexpr T inv(int n) const noexcept { if (n < 0) return 0; return inv_[n]; } constexpr T finv(int n) const noexcept { if (n < 0) return 0; return finv_[n]; } }; // スターリング数 (n 個を k グループにわける、n >= k) template struct Stirling { vector > S; constexpr Stirling(int MAX) noexcept : S(MAX, vector(MAX, 0)) { S[0][0] = 1; for (int n = 1; n < MAX; ++n) { for (int k = 1; k <= n; ++k) { S[n][k] = S[n-1][k-1] + S[n-1][k] * k; } } } constexpr T get(int n, int k) { if (n < 0 || k < 0 || n < k) return 0; return S[n][k]; } }; const int MOD = 1000000007; const int MAX = 600; int main() { // 入力 long long N; cin >> N; using mint = Fp; // 前計算 BiCoef bc(MAX); Stirling sl(MAX); // 求める mint res = 0; for (int n = 0; n <= N; ++n) { for (int k = 0; k <= n; ++k) { res += bc.com(N, n) * sl.get(n, k) * modpow(mint(k*(k-1)), N-n); } } cout << res << endl; }