#define _USE_MATH_DEFINES #include <cstdio> #include <iostream> #include <sstream> #include <fstream> #include <iomanip> #include <algorithm> #include <cmath> #include <complex> #include <string> #include <vector> #include <list> #include <queue> #include <stack> #include <set> #include <map> #include <bitset> #include <numeric> #include <limits> #include <climits> #include <cfloat> #include <functional> #include <iterator> using namespace std; void mod_inverse(int n, vector<long long>& inv, int mod) { inv.assign(n+1, -1); inv[1] = 1; for(int i=2; i<=n; ++i) inv[i] = inv[mod % i] * (mod - mod / i) % mod; } class FactorialCalculation { private: const int mod; vector<long long> factorial; vector<long long> invFactorial; public: FactorialCalculation(int n, int mod) : mod(mod) { factorial.resize(n+1, 1); invFactorial.resize(n+1, 1); vector<long long> inv; mod_inverse(n, inv, mod); for(int i=1; i<=n; ++i){ factorial[i] = factorial[i-1] * i % mod; invFactorial[i] = invFactorial[i-1] * inv[i] % mod; } } long long getFactorial(int n){ return factorial[n]; } long long getInvFactorial(int n){ return invFactorial[n]; } long long getPermutation(int n, int r){ if(n < r) return 0; return factorial[n] * invFactorial[n-r] % mod; } long long getCombination(int n, int r){ if(n < r) return 0; return getPermutation(n, r) * invFactorial[r] % mod; } long long getHomogeneous(int n, int r){ return getCombination(n+r-1, r); } }; const int MOD = 1000000007; long long power(int a, int b) { long long ret = 1; long long tmp = a; while(b > 0){ if(b & 1){ ret *= tmp; ret %= MOD; } tmp *= tmp; tmp %= MOD; b >>= 1; } return ret; } int main() { int n; cin >> n; FactorialCalculation fc(2*n, MOD); long long ans = 0; for(int i=1; i<=n; ++i){ ans += fc.getCombination(n, i) * power(i, n-i); ans %= MOD; } cout << ans << endl; return 0; }