#include <bits/stdc++.h>
using namespace std;

#define _p(...) (void)printf(__VA_ARGS__)
#define forr(x,arr) for(auto&& x:arr)
#define _overload3(_1,_2,_3,name,...) name
#define _rep2(i,n) _rep3(i,0,n)
#define _rep3(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload3(__VA_ARGS__,_rep3,_rep2,)(__VA_ARGS__)
#define _rrep2(i,n) _rrep3(i,0,n)
#define _rrep3(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define rrep(...) _overload3(__VA_ARGS__,_rrep3,_rrep2,)(__VA_ARGS__)
#define ALL(x) (x).begin(), (x).end()
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
#define fst first
#define snd second
using ll=long long;using pii=pair<int,int>;using vb=vector<bool>;
using vi=vector<int>;using vvi=vector<vi>;using vvvi=vector<vvi>;
using vl=vector<ll>;using vvl=vector<vl>;using vvvl=vector<vvl>;
using vd=vector<double>;using vvd=vector<vd>;using vvvd=vector<vvd>;
using vpii=vector<pii>;using vvpii=vector<vpii>;using vvvpii=vector<vvpii>;

const long long mod = 1000;

template<int MOD>
struct Mint {
  int x;
  Mint() : x(0) {}
  Mint(int y) : x(y >= 0 ? y % MOD : MOD - (-y) % MOD) {}
  Mint(signed long long sll) : x(sll % MOD) { if (x < 0) x += MOD; }
  Mint &operator+=(const Mint &rhs){ if((x += rhs.x) >= MOD) x -= MOD; return *this; }
  Mint &operator-=(const Mint &rhs){ if((x += MOD - rhs.x) >= MOD) x -= MOD; return *this; }
  Mint &operator*=(const Mint &rhs){ x = 1LL*x*rhs.x % MOD; return *this; }
  Mint &operator/=(const Mint &rhs){ x = (1LL*x*rhs.inv().x) % MOD; return *this; }
  Mint operator-() const { return Mint(-x); }
  Mint operator+(const Mint &rhs) const { return Mint(*this) += rhs; }
  Mint operator-(const Mint &rhs) const { return Mint(*this) -= rhs; }
  Mint operator*(const Mint &rhs) const { return Mint(*this) *= rhs; }
  Mint operator/(const Mint &rhs) const { return Mint(*this) /= rhs; }
  bool operator<(const Mint &rhs) const { return x < rhs.x; }
  Mint inv() const {
    signed a = x, b = MOD, u = 1, v = 0, t;
    while(b){ t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); }
    return Mint(u);
  }
  Mint operator^(unsigned long long t) const {
    Mint e = *this, res = 1;
    for(; t; e *= e, t>>=1) if (t & 1) res *= e;
    return res;
  }
};
template<int MOD> ostream &operator<<(ostream &os, const Mint<MOD> &rhs) { return os << rhs.x; }
template<int MOD> istream &operator>>(istream &is, Mint<MOD> &rhs) { long long s; is >> s; rhs = Mint<MOD>(s); return is; };

using mint = Mint<mod>;

template<typename T, int N>
struct matrix_ {
  array<T, N*N> val;

  matrix_(vector<vector<T>> ini) {
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++)
      val[i * N + j] = ini[i][j];
  }

  // d=0: zero matrix, d=1: identity matrix
  matrix_(int d = 0) {
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++)
      val[i * N + j] = T((i == j) * d);
  }

  matrix_ operator+(const matrix_ &x) const {
    matrix_ ret;
    for (int i = 0; i < N; i++) for (int j = 0; j < N; j++) {
      ret.val[i * N + j] = val[i * N + j] + x.val[i * N + j];
      //if (ret.val[i * N + j] > mod) ret.val[i * N + j] -= mod;
    }
    return ret;
  }

  matrix_ operator*(const matrix_ &x) const {
    matrix_ ret;
    for (int i = 0; i < N; i++) for (int k = 0; k < N; k++) for (int j = 0; j < N; j++) {
      ret.val[i * N + j] += val[i * N + k] * x.val[k * N + j];
      //if (ret.val[i * N + j] > mod) ret.val[i * N + j] %= mod;
    }
    return ret;
  }

  matrix_ operator^(unsigned long long p) const {
    matrix_ ret(1);
    matrix_ x(*this);
    while (p) {
      if (p & 1) ret = ret * x;
      x = x * x;
      p >>= 1;
    }
    return ret;
  }

  T& at(int row, int col) {
    return val[row * N + col];
  }
};
using Mat = matrix_<mint, 2>;
const Mat ini({{1,1}, {1,0}});

void Main() {
  int n;
  scanf("%d", &n);
  Mat A({{1,3},{1,1}});
  Mat B = A ^ n;
  mint a = B.at(0, 0);
  a *= 2;

  if (n % 2 == 0) a -= 1;
  cout << a << endl;
}
int main() { cin.tie(0); ios::sync_with_stdio(false); Main(); return 0; }