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

const int MOD7 = ( int ) 1e9 + 7;

typedef vector< int > vi;
typedef vector< vi > vvi;

signed main(){
  int N; cin >> N;
  vvi dp = vvi( N + 1, vi( 3 ) );
  dp[ 0 ][ 0 ] = 1;
  for( int i = 0; i < N; ++i )
    ( dp[ i + 1 ][ 0 ] += ( dp[ i ][ 1 ] + dp[ i ][ 2 ] ) % MOD7 ) %= MOD7,
    ( dp[ i + 1 ][ 1 ] += dp[ i ][ 0 ] ) %= MOD7,
    ( dp[ i + 1 ][ 2 ] += dp[ i ][ 1 ] ) %= MOD7;
  cout << ( ( dp[ N ][ 0 ] + dp[ N ][ 1 ] ) % MOD7 + dp[ N ][ 2 ] ) % MOD7 << endl;
  return 0;
}