#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);
const int MOD = 1e9 + 7;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  vector<vector<int> > dp(n+1, vector<int>(3));
  dp[0][0] = 1;

  for (int i = 1; i <= n; i++) {
    for (int j = 0; j < 3; j++) {
      if (i < j+1) continue;
      for (int k = 0; k < 3; k++) {
        if (i-j-1 == 0 || k != j)
          dp[i][j] = (dp[i][j] + dp[i-j-1][k]) % MOD;
      }
    }
  }

  int ret = 0;
  REP (i, 3) ret = (ret + dp[n][i]) % MOD;
  cout << ret << endl;
  
  return 0;
}