#include <bits/stdc++.h>
#define rep(i,n) for(int i=(0);i<(n);i++)

using namespace std;

typedef long long ll;

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	ll n;
	cin >> n;

	ll MOD = 1e9 + 7;

	ll dp[n+5][4];
	rep(i, n+5) rep(j, 4) dp[i][j] = 0;
	dp[1][1] = dp[2][2] = dp[3][3] = 1;
	for(int i = 1; i <= n; i++){
		for(int j = 1; j <= 3; j++){
			if(j != 1) {dp[i+j][j] += dp[i][1]; dp[i+j][j] %= MOD;}
			if(j != 2) {dp[i+j][j] += dp[i][2]; dp[i+j][j] %= MOD;}
			if(j != 3) {dp[i+j][j] += dp[i][3]; dp[i+j][j] %= MOD;}
		}
	}

	cout << (dp[n][1] + dp[n][2] + dp[n][3]) % MOD << endl;
}