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

ll MOD = 1e9 + 7;
ll dp[(int)1e6+10][4];

int main(void) {
    ll N;
    cin >> N;
    dp[1][1] = 1;
    dp[2][2] = 1;
    dp[3][1] = 1;
    dp[3][2] = 1;
    dp[3][3] = 1;
    for (int i = 4; i <= N; i++) {
        dp[i][1] = (dp[i-1][2] + dp[i-1][3]) % MOD;
        dp[i][2] = (dp[i-2][1] + dp[i-2][3]) % MOD;
        dp[i][3] = (dp[i-3][1] + dp[i-3][2]) % MOD;
    }
    cout << ( dp[N][1] + dp[N][2] + dp[N][3] ) % MOD << endl;
    return 0;
}