#include <iostream>
#include <vector>
using namespace std;

int n;
int memo[1000000][3];

int solve(int t, int k) {
  if (t >= n) return 1;
  if (memo[t][k] != -1) return memo[t][k];
  int ret = 0;
  if (k + 1 < 3) ret += solve(t + 1, k + 1) % 1000000007;
  if (k != 0)    ret += solve(t + 1, 0) % 1000000007;
  return memo[t][k] = ret;
}

int main(void) {
  cin >> n;
  for (int i = 0; i < 1000000; i++) {
    for (int j = 0; j < 3; j++) memo[i][j] = -1;
  }
  cout << solve(0, 0) << endl;
  return 0;
}