#include <iostream>
using namespace std;

const int mod = 1000000007;
int dp[1000001][4];

int main(void) {
    int N;
    cin >> N;

    dp[1][1] = 1;
    dp[2][2] = 1; 
    dp[3][1] = 1; 
    dp[3][2] = 1; 
    dp[3][3] = 1; 

    for (int i = 4; i <= N; i++) {
        for (int j = 1; j <= 3; j++) {
            for (int k = 1; k <= 3; k++) {
                if (j == k) continue;
                dp[i][j] = (dp[i][j] + dp[i-j][k]) % mod;
            }
        }
    }

    int ans = 0;
    for (int i = 1; i <= 3; i++) ans = (ans + dp[N][i]) % mod;

    cout << ans << endl;
    return 0;
}