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

using ll = long long;
using P = pair<int, int>;

const int INF = 1e9;
const int MOD = 1e9 + 7;
const int MAX = 1e6 + 10;

int dp[MAX];

int main() {
  int N;
  cin >> N;

  dp[0] = 1;
  dp[1] = dp[2] = 2;
  for (int i = 3; i < N; i++) {
    dp[i] = dp[i-2] + dp[i-3];
    dp[i] %= MOD;
  }

  cout << dp[N-1] << endl;
  return 0;
}