#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define o(a) cout << a << endl
#define int long long
#define fi first
#define se second
using namespace std;
typedef pair<int, int> P;

const int mod = 1e9 + 7;
int dp[1000010][3];

signed main(){
    int n;
    cin >> n;
    dp[1][0] = 1;
    dp[2][1] = 1;
    dp[3][2] = 1;
    // rep(i, 0, 3) dp[0][i] = 1;
    rep(i, 1, n + 1){
        rep(j, 0, 3){
            rep(k, 0, 3){
                if(j == k || i - (j + 1) < 0) continue;
                dp[i][j] = (dp[i][j] + dp[i - (j + 1)][k]) % mod; 
            }
        }
    }
    // rep(i, 0, n + 1){
    //     rep(j, 0, 3){
    //         cout << dp[i][j] << " ";
    //     }
    //     cout << endl;
    // }
    int ans = 0;
    rep(i, 0, 3) ans += dp[n][i];
    cout << ans % mod << endl;
}