#include "bits/stdc++.h"
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,x,n) for(int i=x;i<n;i++)
#define ALL(v) (v).begin(),(v).end()
#define MP(a,b) make_pair(a,b)
typedef long long LL;
typedef pair<int, int> PI;
typedef vector<int> VI;
const LL MOD = 1000000007LL;
LL dp[1000001][3];
int main() {
	int N;
	cin >> N;
	dp[0][0] = 1;
	rep(i, N) {
		//ken
		dp[i + 1][1] = dp[i][0];
		dp[i + 1][2] = dp[i][1];
		//pa
		dp[i + 1][0] = dp[i][1];
		dp[i + 1][0] = (dp[i + 1][0] + dp[i][2]) % MOD;
	}
	LL ans = dp[N][0];
	ans = (ans + dp[N][1]) % MOD;
	ans = (ans + dp[N][2]) % MOD;
	cout << ans << endl;
}