#include <cstdio>
#include <cassert>
#include <ctime>

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <utility>

#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define rep3(i, m, n) for (int i = int(m); i < int(n); ++i)

using namespace std;
using uint64 = unsigned long long;
using uint32 = unsigned;

void solve() {
  const int MOD = 1e9 + 7;
  int N;
  while (~scanf("%d", &N)) {
    int p = 1;
    int k1 = 0;
    int k2 = 0;
    rep(i, N) {
      int t = p;
      p = (k1 + k2) % MOD;
      k2 = k1;
      k1 = t;
    }
    int ans = (uint64(p) + k2 + k1) % MOD;
    printf("%d\n", ans);
  }
}

int main() {
  solve();
  return 0;
}