#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int (i)=(0);(i)<(int)(n);++(i))
using ll = long long;

const int mod = 1e9 + 7;

ll dp[4][1000000+10];



int main() {
    int N; cin >> N;

    dp[1][1] = 1;
    dp[2][2] = 1;
    dp[3][3] = 1;

    for (int i=1; i<N; ++i) {
        dp[1][i+1] = (dp[1][i+1] + dp[2][i] + dp[3][i]) % mod;
        dp[2][i+2] = (dp[2][i+2] + dp[1][i] + dp[3][i]) % mod;
        dp[3][i+3] = (dp[3][i+3] + dp[1][i] + dp[2][i]) % mod;
    }

    cout << (dp[1][N] + dp[2][N] + dp[3][N]) % mod << endl;

}