#pragma region include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include //#include #include #pragma endregion //#include ///////// #define REP(i, x, n) for(int i = x; i < n; ++i) #define rep(i,n) REP(i,0,n) ///////// #pragma region typedef typedef long long LL; typedef long double LD; typedef unsigned long long ULL; #pragma endregion //typedef ////定数 const int INF = (int)1e9; const LL MOD = (LL)1e9+7; const LL LINF = (LL)1e18; const double PI = acos(-1.0); const double EPS = 1e-9; ///////// using namespace::std; ///////// #pragma region Math #pragma region template inline T gcd(T a, T b){return b ? gcd(b, a % b) : a;} #pragma endregion // 最大公約数 gcd #pragma region template inline T lcm(T a, T b){return a / gcd(a, b) * b;} #pragma endregion // 最小公倍数 lcm #pragma region LL powMod(LL num,LL n,LL mod=(LL)MOD){//(num**n)%mod num %= mod;// if( n == 0 ){ return (LL)1; } LL mul = num; LL ans = (LL)1; while(n){ if( n&1 ){ ans = (ans*mul)%mod; } mul = (mul*mul)%mod; n >>= 1; } return ans; } LL mod_inverse(LL num,LL mod=MOD){ return powMod(num,MOD-2,MOD); } #pragma endregion //繰り返し二乗法 powMod void solve(){ LL N; cin >> N; LL inv = mod_inverse(2); LL invN = powMod(inv,N); LL temp = 2*N; LL ans=1; for(int i=1;i<=temp;++i){ ans = (ans * i) % MOD; } ans = (ans * invN ) % MOD; cout << ans << endl; } #pragma region main signed main(void){ std::cin.tie(0); std::ios::sync_with_stdio(false); std::cout << std::fixed;//小数を10進数表示 cout << setprecision(16);//小数点以下の桁数を指定//coutとcerrで別 solve(); } #pragma endregion //main()