#include using namespace std; struct Initializer { Initializer() { cin.tie(0); ios::sync_with_stdio(0); cout << fixed << setprecision(15); } } initializer; template class Addition { public: template T operator+(const V& v) const { return T(static_cast(*this)) += v; } }; template class Subtraction { public: template T operator-(const V& v) const { return T(static_cast(*this)) -= v; } }; template class Multiplication { public: template T operator*(const V& v) const { return T(static_cast(*this)) *= v; } }; template class Division { public: template T operator/(const V& v) const { return T(static_cast(*this)) /= v; } }; template class Modulus { public: template T operator%(const V& v) const { return T(static_cast(*this)) %= v; } }; template class IndivisibleArithmetic : public Addition, public Subtraction, public Multiplication {}; template class Arithmetic : public IndivisibleArithmetic, public Division {}; class Inverse { private: long long mod; vector inv; public: Inverse() {} Inverse(long long mod, long long n = 1000000) : mod(mod), inv(n, 1) {for (int i = 2; i < n; ++i) inv[i] = inv[mod % i] * (mod - mod / i) % mod;} long long operator()(long long a) const { if (a < (int)inv.size()) return inv[a]; long long b = mod, x = 1, y = 0; while (b) { long long t = a / b; swap(a -= t * b, b); swap(x -= t * y, y); } return (x %= mod) < 0 ? x + mod : x; } }; class Mint : public Arithmetic { private: static long long mod; static Inverse inverse; long long val; public: Mint() : val(0) {} Mint(const long long& val) { this->val = val % mod; if (this->val < 0) this->val += mod; } static void setMod(const long long& m) { mod = m; inverse = Inverse(m); } Mint operator+=(const Mint& m) { val += m.val; if (val >= mod) val -= mod; return *this; } Mint operator-=(const Mint& m) { val -= m.val; if (val < 0) val += mod; return *this; } Mint operator*=(const Mint& m) { val *= m.val; val %= mod; return *this; } Mint operator/=(const Mint& m) { val *= inverse(m.val); val %= mod; return *this; } Mint operator++() {return *this += 1;} Mint operator--() {return *this -= 1;} operator long long() {return val;} Mint identity() const {return 1;} }; long long Mint::mod = 1000000007; Inverse Mint::inverse(1000000007); ostream& operator<<(ostream& os, Mint a) { os << (long long)a; return os; } istream& operator>>(istream& is, Mint& a) { long long n; is >> n; a = n; return is; } template T pow(const T& m, long long n) { if (n == 0) { return m.identity(); } else if (n < 0) { return m.identity() / pow(m, -n); } T mm = pow(m, n / 2); mm *= mm; if (n % 2) mm *= m; return mm; } template class Ordered { public: template bool operator==(const V& v) const { return !(static_cast(v) < static_cast(*this) || static_cast(*this) < static_cast(v)); } template bool operator!=(const V& v) const { return static_cast(v) < static_cast(*this) || static_cast(*this) < static_cast(v); } template bool operator>(const V& v) const { return static_cast(v) < static_cast(*this); } template bool operator<=(const V& v) const { return !(static_cast(v) < static_cast(*this)); } template bool operator>=(const V& v) const { return !(static_cast(*this) < static_cast(v)); } }; template class Vector : public Addition>, public Subtraction>, public Ordered> { protected: vector val; public: Vector(int n) : val(n, 0) {} T& operator[](int n) { return val[n]; } Vector operator+=(const Vector& v) { for (int i = 0; i < size(); ++i) val[i] += v[i]; return *this; } Vector operator-=(const Vector& v) { for (int i = 0; i < size(); ++i) val[i] -= v[i]; return *this; } T operator*(const Vector& v) const { return inner_product(val.begin(), val.end(), const_cast(v).begin(), T(0)); } bool operator<(const Vector& v) const { if (size() != v.size()) return size() < v.size(); for (int i = 0; i < size(); ++i) if (val[i] != v.val[i]) return val[i] < v.val[i]; return false; } int size() const { return val.size(); } typename vector::const_iterator begin() const { return val.begin(); } typename vector::const_iterator end() const { return val.end(); } }; template class Matrix : public Addition>, public Subtraction>, public Ordered> { protected: vector> val; public: Matrix(int n, int m) : val(n, Vector(m)) {} Vector& operator[](int n) {return val[n];} Matrix operator+=(const Matrix& m) { for (int i = 0; i < (int)val.size(); ++i) val[i] += m[i]; return *this; } Matrix operator-=(const Matrix& m) { for (int i = 0; i < (int)val.size(); ++i) val[i] -= m[i]; return *this; } Matrix operator*=(const Matrix& _m) { Matrix &m = const_cast(_m); Matrix res(size(), m[0].size()); for (int i = 0; i < size(); ++i) { for (int j = 0; j < m.size(); ++j) { for (int k = 0; k < m[0].size(); ++k) { res[i][k] += val[i][j] * m[j][k]; } } } return *this = res; } Matrix operator*(const Matrix& m) const { Matrix res = *this; return res *= m; } Vector operator*(const Vector& v) { Vector res(size()); for (int i = 0; i < size(); ++i) res[i] += val[i] * v; return res; } bool operator<(const Matrix& m) const { if (size() != m.size()) return size() < m.size(); for (int i = 0; i < size(); ++i) if (val[i] != m.val[i]) return val[i] < m.val[i]; return false; } int size() const { return val.size(); } }; template class SquareMatrix : public Matrix, public Division> { public: SquareMatrix(int n) : Matrix(n, n) {} SquareMatrix(const Matrix& m) : Matrix(m) {} SquareMatrix operator/=(const SquareMatrix& m) { return *this *= m.inverse(); } SquareMatrix identity() const { SquareMatrix res(this->size()); for (int i = 0; i < this->size(); ++i) res[i][i] = 1; return res; } SquareMatrix inverse() const { int n = this->size(); SquareMatrix mat = *this; SquareMatrix inv = identity(); for (int i = 0; i < n; ++i) { int p = i; for (int j = i + 1; j < n; ++j) { if (abs(mat[j][i]) > abs(mat[p][i])) p = j; } swap(mat[i], mat[p]); swap(inv[i], inv[p]); for (int j = i + 1; j < n; ++j) mat[i][j] /= mat[i][i]; for (int j = 0; j < n; ++j) inv[i][j] /= mat[i][i]; mat[i][i] = 1; for (int j = 0; j < n; ++j) { if (i == j) continue; T a = mat[j][i]; for (int k = 0; k < n; ++k) { mat[j][k] -= a * mat[i][k]; inv[j][k] -= a * inv[i][k]; } } } return inv; } }; int main() { int n; cin >> n; SquareMatrix mat(3); mat[0][1] = 1; mat[0][2] = 1; mat[1][0] = 1; mat[2][1] = 1; mat = pow(mat, n - 1); cout << accumulate(mat[0].begin(), mat[0].end(), Mint()) << endl; }