#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

ll dp[1000100][3];
const ll MOD = 1e9 + 7;

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

    int N;
    std::cin >> N;

    dp[1][1] = 1ll;
    dp[2][2] = 1ll;
    dp[3][3] = 1ll;
    for(int i=1;i<N;++i){
        for(int j=1;j<=3;++j){
            for(int k=1;k<=3;++k){
                if(k == j){continue;}
                if(i + k > N){continue;}

                dp[i + k][k] = (dp[i + k][k] + dp[i][j]) % MOD;
            }
        }
    }

    ll res = 0ll;
    for(int i=1;i<=3;++i){
        res = (res + dp[N][i]) % MOD;
    }
    
    std::cout << res << std::endl;
}