#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
typedef long long ll;
#define M 1000000007
ll n;
ll dp[2][3];
int main(void){
    cin>>n;
    dp[0][0]=1;
    for(int i=0;i<n;i++){
        int u=(i+1)%2;
        dp[u][0]=(dp[i%2][1]+dp[i%2][2])%M;
        dp[u][1]=dp[i%2][0];
        dp[u][2]=dp[i%2][1];
    }
    cout<<((dp[n%2][0]+dp[n%2][1])%M+dp[n%2][2])%M<<endl;
}