#pragma GCC optimize ("O3") #include "bits/stdc++.h" using namespace std; using ll = long long int; #define debugos cout #define debug(v) {printf("L%d %s > ",__LINE__,#v);debugos<<(v)< ",__LINE__,#v);for(auto e:(v)){debugos< ",__LINE__,#m);for(int x=0;x<(w);x++){debugos<<(m)[x]<<" ";}debugos<\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){debugos<<(m)[y][x]<<" ";}debugos<::type>::type cnt=0;(cnt)<(l);++(cnt)) #define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt)) #define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt)) #define diterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);--(cnt)) const ll MD = 1000000007ll; const long double PI = 3.1415926535897932384626433832795L; inline void assert_call(bool assertion, function f) { if (!assertion) { cerr << "assertion fault:" << endl; f(); abort(); } } template inline ostream& operator <<(ostream &o, const pair p) { o << '(' << p.first << ':' << p.second << ')'; return o; } template inline ostream& _ostream_vecprint(ostream& os, const Vec& a) { os << '['; for (const auto& e : a) os << ' ' << e << ' '; os << ']'; return os; } template inline ostream& operator<<(ostream& o, const vector& v) { return _ostream_vecprint(o, v); } template inline ostream& operator<<(ostream& o, const array& v) { return _ostream_vecprint(o, v); } template inline T& maxset(T& to, const T& val) { return to = max(to, val); } template inline T& minset(T& to, const T& val) { return to = min(to, val); } void bye(string s, int code = 0) { cout << s << endl; exit(code); } mt19937_64 randdev(8901016); template inline T rand(T l, T h) { return uniform_int_distribution(l, h)(randdev); } template<> inline double rand(double l, double h) { return uniform_real_distribution(l, h)(randdev); } template<> inline float rand(float l, float h) { return uniform_real_distribution(l, h)(randdev); } #if defined(_WIN32) || defined(_WIN64) #define getchar_unlocked _getchar_nolock #define putchar_unlocked _putchar_nolock #elif defined(__GNUC__) #else #define getchar_unlocked getchar #define putchar_unlocked putchar #endif namespace { #define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E) class MaiScanner { public: template void input_integer(T& var) noexcept { var = 0; T sign = 1; int cc = getchar_unlocked(); for (; cc < '0' || '9' < cc; cc = getchar_unlocked()) if (cc == '-') sign = -1; for (; '0' <= cc && cc <= '9'; cc = getchar_unlocked()) var = (var << 3) + (var << 1) + cc - '0'; var = var * sign; } inline int c() noexcept { return getchar_unlocked(); } inline MaiScanner& operator>>(int& var) noexcept { input_integer(var); return *this; } inline MaiScanner& operator>>(long long& var) noexcept { input_integer(var); return *this; } inline MaiScanner& operator>>(string& var) { int cc = getchar_unlocked(); for (; !isvisiblechar(cc); cc = getchar_unlocked()); for (; isvisiblechar(cc); cc = getchar_unlocked()) var.push_back(cc); return *this; } template void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) *this >> *it; } }; class MaiPrinter { public: template void output_integer(T var) noexcept { if (var == 0) { putchar_unlocked('0'); return; } if (var < 0) putchar_unlocked('-'), var = -var; char stack[32]; int stack_p = 0; while (var) stack[stack_p++] = '0' + (var % 10), var /= 10; while (stack_p) putchar_unlocked(stack[--stack_p]); } inline MaiPrinter& operator<<(char c) noexcept { putchar_unlocked(c); return *this; } inline MaiPrinter& operator<<(int var) noexcept { output_integer(var); return *this; } inline MaiPrinter& operator<<(long long var) noexcept { output_integer(var); return *this; } inline MaiPrinter& operator<<(char* str_p) noexcept { while (*str_p) putchar_unlocked(*(str_p++)); return *this; } inline MaiPrinter& operator<<(const string& str) { const char* p = str.c_str(); const char* l = p + str.size(); while (p < l) putchar_unlocked(*p++); return *this; } template void join(IT begin, IT end, char sep = ' ') { for (bool b = 0; begin != end; ++begin, b = 1) b ? *this << sep << *begin : *this << *begin; } }; } MaiScanner scanner; MaiPrinter printer; template class Combinatorics { using value_type = long long; value_type fact_[MaxN + 1]; // value_type inv_[MaxN + 1]; // iranai public: value_type pow(value_type x, value_type p) { value_type y = 1; x = x % Mod; for (; 0 < p; p >>= 1) { if (p & 1) y = y * x % Mod; x = x * x % Mod; } return y; } Combinatorics() :fact_() { fact_[0] = 1; fact_[1] = 1; for (value_type n = 2; n <= MaxN; ++n) fact_[n] = (fact_[n - 1] * n) % Mod; // inv_[Max] := calculate; // iterate => inv_[i] = inv_[i+1] * (i+1) % MD; } inline value_type fact(int n) const { return fact_[n]; } inline value_type inv(value_type n) { return pow(n, MD - 2); } inline value_type nPr(value_type n, value_type r) { if (r < 0 || n < r) return 0; return fact_[n] * inv(fact_[n - r]) % MD; } inline value_type nCr(value_type n, value_type r) { if (n < r) return 0; return ((fact_[n] * inv(fact_[n - r]) % MD) * inv(fact_[r])) % MD; } inline value_type nHr(value_type n, value_type r) { if (n == 0 && r == 0) return 1; if (n == 0) return 0; return nCr(n - 1 + r, n - 1); } }; Combinatorics<600, MD> comb; ll N; // http://kmjp.hatenablog.jp/entry/2015/01/30/0930 // [同じグループに入るペア][全体のグループの数] ll dp[666][666]; int main() { scanner >> N; dp[0][0] = 1; iterate(i, 1ll, N+1) { iterate(j, 1ll, N+1) { dp[i][j] = (dp[i - 1][j - 1] + j * dp[i - 1][j]) % MD; } } ll ans = 0; iterate(i, 0ll, N+1) { iterate(j, 0ll, N+1) { ans += ((comb.nCr(N, i)*dp[i][j])%MD * comb.pow(j * (j - 1), N-i)) % MD; ans %= MD; } } cout << ans << endl; return 0; }