#include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)< pii; typedef vector vi; typedef vector vll; template class ModInt{ public: ModInt():value(0){} ModInt(long long val):value((int)(val<0?MOD+val%MOD:val%MOD)){ } ModInt& operator+=(ModInt that){ value = value+that.value; if(value>=MOD)value-=MOD; return *this; } ModInt& operator-=(ModInt that){ value -= that.value; if(value<0)value+=MOD; return *this; } ModInt& operator*=(ModInt that){ value = (int)((long long)value * that.value % MOD); return *this; } ModInt &operator/=(ModInt that){ return *this *= that.inverse(); } ModInt operator+(ModInt that) const{ return ModInt(*this)+=that; } ModInt operator-(ModInt that) const{ return ModInt(*this)-=that; } ModInt operator*(ModInt that) const{ return ModInt(*this)*=that; } ModInt operator/(ModInt that) const { return ModInt(*this) /= that; } ModInt pow(long long k) const{ if(value == 0)return 0; ModInt n = *this, res = 1; while(k){ if(k & 1)res *= n; n *= n; k >>= 1; } return res; } ModInt inverse() const { long long a = value, 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); } int toi() const{ return value; } private: int value; }; typedef ModInt<1000000007> mint; ostream& operator<<(ostream& os, const mint& x){ os << x.toi(); return os; } mint dp[556][556][556]; int main(){ int N; cin >> N; dp[0][0][0] = 1; rep(i, N){ for(int j = i; j >= 0; --j)for(int k = i; k >= 0; --k){ int x = dp[i][j][k].toi(); if(!x)continue; // グループを作る dp[i+1][j + 1][k] += x; // どこのグループにも入れない dp[i+1][j][k + 1] += x; // どこかのグループに入れる dp[i + 1][j][k] += (ll)x*j; } } mint ans; rep(i, N + 1)rep(j, N + 1){ if(!dp[N][i][j].toi())continue; if(j == 0){ ans += dp[N][i][j]; } else{ mint x = dp[N][i][j] * mint(i*(i - 1)).pow(j); ans += x; } } cout << ans << endl; }