#include <bits/stdc++.h>
#include <cmath>
#include <climits>
#include <cstdio>

using namespace std;

#define endl '\n'
#define PB push_back
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define AALL(a,n) (a),(a)+(n)

typedef pair<int,int> P;
typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<LL,LL> LP;

LL dp[1000000+10][3];
const int mod = 1000000007;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int N;
	cin >> N;
	dp[0][1] = dp[0][2] = 0;
	dp[0][0] = 1;
	FOR(i,1,N+1){
		dp[i][0] = (dp[i-1][1]+dp[i-1][2])%mod;
		dp[i][1] = (dp[i-1][0])%mod;
		dp[i][2] = dp[i-1][1]%mod;
	}
	cout << (dp[N][0]+dp[N][1]+dp[N][2])%mod << endl;
	return 0;
}