#include <bits/stdc++.h>
using namespace std;

using int64 = long long;
using uint64 = unsigned long long;

constexpr int64 MOD = 1e9 + 7;

int64 table[1000001][4];

int main()
{
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int N;
    cin >> N;

    table[0][0] = 1;
    for (int i = 0; i < N; i++)
    {
        for (int pre = 0; pre <= 3; pre++)
        {
            if (table[i][pre] == 0) continue;

            for (int step = 1; step <= 3; step++)
            {
                if (pre != step and i + step <= N)
                {
                    (table[i + step][step] += table[i][pre]) %= MOD;
                }
            }
        }
    }
    cout << (table[N][1] + table[N][2] + table[N][3]) % MOD << endl;

    return 0;
}