#include <cmath>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <functional>
#include <queue>
#include <iostream>
#include <string.h>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdint>
#include <climits>
#include <unordered_set>
#include <sstream>
#include <stack>

using namespace std;

typedef long long int ll;
typedef pair<int,int> pii;
typedef tuple<int,int,int> t3;

vector<ll> dp[4];

int main()
{
    ll n;
    cin >> n;
    if(n == 1)
    {
        cout << 1 << endl;
    }
    if(n == 2)
    {
        cout << 1 << endl;
    }
    if(n == 3)
    {
        cout << 3 << endl;
    }
    for(int i = 1;i <= 3;i++)
    {
        dp[i].assign(n + 10, 0);
    }
    const ll mod = 1e9 + 7;
    dp[1][1] = 1;
    dp[1][2] = 0;
    dp[1][3] = 1;
    dp[2][2] = 1;
    dp[2][3] = 1;
    dp[3][3] = 1;
    for(int i = 4;i <= n;i++)
    {
        dp[1][i] = dp[2][i-1] + dp[3][i-1];
        dp[2][i] = dp[1][i-2] + dp[3][i-2];
        dp[3][i] = dp[1][i-3] + dp[2][i-3];
        for(int j = 1;j <= 3;j++)
        {
            dp[j][i] %= mod;
        }
    }
    ll sum = 0;
    for(int j = 1;j <= 3;j++)
    {
        sum += dp[j][n];
        sum %= mod;
    }
    cout << sum << endl;
    return 0;
}