#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n, o = 0, e = 0;
  cin >> n;
  long long dp[n];
  dp[0] = 1;
  dp[1] = 2;
  o = 1;
  e = 3;
  for (long long i = 2; i < n; i++) {
    dp[i] = (dp[i - 1] + dp[i - 2]) % 1000000007;
  }
  for (long long i = 1; i < n; i++) dp[i] = (dp[i] + dp[i - 1]) % 1000000007;
  cout << dp[n - 1] << endl;
}
int32_t main() {
  long long t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
