#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <string>
#include <queue>
#include <stack>
#include <math.h>
#include <set>
#include <cstdio>
#define ALL(obj) (obj).begin(),(obj).end()
#define RALL(obj) (obj).rbegin(),(obj).rend()
#define P pair<int, int>

#define MOD 1000000007
#define INF 1012345678
#define NINF (-2147483647-1)
#define LLINF 9223372036854775807
using ll = long long;
using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;
    // dp[i][j] := i+1段目にいて前回j+1stepjumpした
    vector<vector<int>> dp(N, vector<int>(3, 0));
    for (int i = 0; i < min(3,N); i++)
    {
        dp[i][i] = 1;
    }
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            for (int k = 0; k < 3; k++)
            {
                if (j != k && i + k + 1 < N) {
                    dp[i + k + 1][k] += dp[i][j];
                    dp[i + k + 1][k] %= MOD;
                }
            }
        }
    }
    int ans = 0;
    for (int i = 0; i < 3; i++)
    {
        ans += dp[N - 1][i];
        ans %= MOD;
    }
    cout << ans << endl;
    getchar(); getchar();
}