#include <limits> #include <iostream> #include <algorithm> #include <vector> #include <iomanip> #include <map> #include <queue> static const int MOD = 1000000007; using ll = long long; using u32 = unsigned; using namespace std; template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208; template <class T, size_t D> struct _Vec { using type = vector<typename _Vec<T, D-1>::type>; }; template <class T> struct _Vec<T, 1> { using type = vector<T>; }; template<class T, size_t D> using Vec = typename _Vec<T, D>::type; template <class T> vector<T> make_v(size_t size, const T& init){ return vector<T>(size, init); } template<class... Ts> auto make_v(size_t size, Ts... rest) { return vector<decltype(make_v(rest...))>(size, make_v(rest...)); } int main() { int n; cin >> n; Vec<int, 2> v = make_v(n, 10, 0); for (int i = 0; i < 10; ++i) { v[0][i] = 1; } for (int i = 1; i < n; ++i) { for (int j = 0; j < 10; ++j) { for (int k = 0; k <= j; ++k) { v[i][j] = (v[i][j] + v[i-1][k]) % MOD; } } } ll ans = 0; for (int i = 0; i < 10; ++i) { ans = (ans + v[n-1][i]) % MOD; } cout << ans << "\n"; return 0; }