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

#define FOR(i,l,r) for(int i = (int) (l);i < (int) (r);i++)
template<typename T> bool chmax(T& a,const T& b){ return a < b ? (a = b,true) : false; }
template<typename T> bool chmin(T& a,const T& b){ return b < a ? (a = b,true) : false; }
typedef long long ll;

int N;
const int MAX_N = 1000000;
ll dp [MAX_N + 1] [4];
const ll MOD = 1e9 + 7;

int main()
{
	scanf("%d",&N);

	dp [0] [0] = 1;
	FOR(i,0,N) FOR(j,0,4){
		if(j != 1 && i + 1 <= N) (dp [i + 1] [1] += dp [i] [j]) %= MOD;
		if(j != 2 && i + 2 <= N) (dp [i + 2] [2] += dp [i] [j]) %= MOD;
		if(j != 3 && i + 3 <= N) (dp [i + 3] [3] += dp [i] [j]) %= MOD;
	}

	ll ans = accumulate(dp [N],dp [N + 1],0ll) % MOD;
	printf("%lld\n",ans);

	return 0;
}