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

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

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 MOD = 1e9 + 7;

	int n;
	cin >> n;

	vector<vector<ll>> dp(n+1, vector<ll>(3, 0ll));
	dp[0][0] = 1ll;
	for(int i = 1; i <= n; i++){
		dp[i][0] += dp[i-1][1] + dp[i-1][2];
		dp[i][0] %= MOD;

		dp[i][1] += dp[i-1][0];
		dp[i][1] %= MOD;

		dp[i][2] += dp[i-1][1];
		dp[i][2] %= MOD;
	}

	cout << (dp[n][0] + dp[n][1] + dp[n][2]) % MOD << endl;
}