#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll mod=1000000007;
ll inf=999999999999999999;
int main(){
    ll n;
    cin >> n;
    vector<vector<ll>>dp(n+10,vector<ll>(4,0));
    dp[1][1]=1;
    dp[2][2]=1;
    dp[3][3]=1;
    for (ll i = 1; i < n; i++)
    {
        for (ll j = 1; j <= 3; j++)
        {
            for (ll k = 1; k <= 3; k++)
            {
                if (j==k)
                {
                    continue;
                }
                dp[i+k][k]+=dp[i][j];
                dp[i+k][k]%=mod;
            }
        }
    }
    ll ans=dp[n][1]+dp[n][2]+dp[n][3];
    ans%=mod;
    cout << ans << endl;
}