#include using namespace std; #define REP(i,n) for(int i=0;i<(int)(n);++i) #define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i) #define ALL(c) (c).begin(), (c).end() #define valid(y,x,h,w) (0<=y&&y pii; templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (bbasic_ostream& operator<<(basic_ostream&os, const C& c){os<<'[';for(auto i=begin(c);i!=end(c);++i)os<<(i==begin(c)?"":" ")<<*i;return os<<']';} templateostream&operator<<(ostream &o,const pair&t){return o<<'('<void output(ostream&,const Tp&){} templatevoid output(ostream &o,const Tp&t){if(N)o<<',';o<(t);output(o,t);} templateostream&operator<<(ostream&o,const tuple&t){o<<'(';output<0,tuple,Ts...>(o,t);return o<<')';} templatevoid output(T t,char z=10){if(t<0)t=-t,putchar(45);int c[20]; int k=0;while(t)c[k++]=t%10,t/=10;for(k||(c[k++]=0);k;)putchar(c[--k]^48);putchar(z);} templatevoid outputs(T t){output(t);} templatevoid outputs(S a,T...t){output(a,32);outputs(t...);} templatevoid output(T *a,int n){REP(i,n)cout<void output(T *a,int n,int m){REP(i,n)output(a[i],m);} templatebool input(T &t){int n=1,c;for(t=0;!isdigit(c=getchar())&&~c&&c-45;); if(!~c)return 0;for(c-45&&(n=0,t=c^48);isdigit(c=getchar());)t=10*t+c-48;t=n?-t:t;return 1;} templatebool input(S&a,T&...t){input(a);return input(t...);} templatebool inputs(T *a, int n) { REP(i,n) if(!input(a[i])) return 0; return 1;} template struct ModInt { int x; ModInt() : x(0) {} ModInt(ll s) { if ((x = s % MOD) < 0) x += MOD; } ModInt operator+=(ModInt rhs) { if ((x+=rhs.x) >= MOD) x -= MOD; return *this; } ModInt operator-=(ModInt rhs) { if ((x-=rhs.x) < 0) x += MOD; return *this; } ModInt operator*=(ModInt rhs) { x = (ll)x*rhs.x % MOD; return *this; } ModInt operator+(ModInt rhs) const { return ModInt(*this) += rhs; } ModInt operator-(ModInt rhs) const { return ModInt(*this) -= rhs; } ModInt operator*(ModInt rhs) const { return ModInt(*this) *= rhs; } ModInt operator/=(ModInt rhs) { static const ll inv2 = ModInt(2).inv().x; // 2で割るのは特別に保存してみる ll i = (rhs.x == 2 ? inv2 : rhs.inv().x); x = x*i%MOD; return *this; } ModInt operator/(ModInt rhs) const { return ModInt(*this) /= rhs; } ModInt inv() { return pow(MOD-2); } ModInt pow(ll n) const { ModInt r = 1, t = x; for (;n;n>>=1,t*=t) if (n&1) r *= t; return r; } friend ostream& operator<<(ostream &os, const ModInt rhs){ return os << rhs.x; } }; typedef ModInt mint; const int NUM = 2000; mint combi[NUM][NUM]; void calcCombi() { combi[0][0] = 1; REP(i, NUM-1) { combi[i][0] = combi[i][i] = 1; REP(j, i) combi[i+1][j+1] = combi[i][j] + combi[i][j+1]; } } mint dp[NUM][NUM]; // dp[i][j] = i組の夫婦をj個のグループに分ける分け方 int main() { memset(dp,0,sizeof(dp)); dp[0][0] = 1; REP(i,NUM) { REP(j,NUM) { if (i>0&&j>0) dp[i][j] += dp[i-1][j-1]; if (i>0) dp[i][j] += dp[i-1][j]*j; } } calcCombi(); int n; while(cin>>n) { mint ans = 0; for (int g=1; g<=n; ++g) { for (int a=g; a<=n; ++a) { // gグループに分ける // a組は夫婦揃ってグループに入る mint tmp = dp[a][g]; // a組のグループ分ける tmp *= combi[n][a]; // a組のグループの選び方 tmp *= mint(g*(g-1)).pow(n-a); // 残りの夫婦 ans += tmp; } } cout << ans << endl; } }