#include <iostream>
#include <vector>
#include <queue>
#include <map>
using namespace std;
const int mod = 1e9 + 7;

int main(){
    int n;
    cin >> n;

    long long dp[n + 10][3];
    for(int i = 0; i < n + 10; i++){
        for(int j = 0; j < 3; j++){
            dp[i][j] = 0;
        }
    }

    dp[0][0] = 1;
    for(int i = 0; i < n; 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;
    }
    cout << (dp[n][0] + dp[n][1] + dp[n][2]) % mod << endl;
}