#include <iostream>
using namespace std;
typedef long long ll;

int N;
ll dp[10000010][3];
ll mod = 1000000007;

int main(void){
    // Your code here!
    cin >> N;
    for(int i = 0; i <= 1000009; i++) for(int j = 0; j < 2; j++) dp[i][j] = 0;
    dp[0][0] = 1;
    
    for(int i = 0; i <= 1000009; i++){
        dp[i+1][0] += ((dp[i][2] + dp[i][1]) % mod);
        dp[i+1][1] += (dp[i][0] % mod);
        dp[i+1][2] += (dp[i][1] % mod);
    }
    
    ll sum = dp[N][0] + dp[N][1] + dp[N][2];
    cout << sum % mod << endl;
}