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

#define int long long
#define pb push_back 
#define mp make_pair
#define fr first
#define sc second
#define Rep(i, n) for( int i = 0; i < (n); i++ )
#define Rrep(i, a, n) for( int i = (a); i < (n); i++ )
#define All(v) v.begin(), v.end()

typedef pair<int, int> Pii; 
typedef pair<int, Pii> Pip;
const int INF = 1107110711071107;

int n;
int dp[4][1000001];

int func(int prev, int now)
{
  if ( now == n ) return 1;
  if( dp[prev][now] ) return dp[prev][now];

  int ret = 0;
  Rrep(i, 1, 4) {
    if( now + i <= n && prev != i ) ret += func(i, now + i);
  }

  return dp[prev][now] = ret % 1000000007;
}

signed main()
{
  cin >> n;
  
  fill_n(*dp, 4 * 1000001, 0);

  cout << (func(1, 1) + func(2, 2) + func(3, 3)) % 1000000007 << endl;
  return 0;
}