#include <bits/stdc++.h>
using namespace std;
long long mod = 1000000007;
vector<vector<long long>> memo;

long long rec(long long n, int cur){
    if (memo[n][cur] >= 0) return memo[n][cur];
    memo[n][cur] = 0;
    if (n- cur - 1 == 0) memo[n][cur] += memo[0][0];
    if (0 < n - cur - 1){
        for (int i = 0; i < 3; ++i){
            if (0 <  rec(n - cur - 1, i) && i != cur){
                memo[n][cur] = (memo[n][cur] + memo[n - cur - 1][i])%mod;
            }
        }
    }
    return memo[n][cur];
}




int main(){
    long long n; cin >> n;
    memo.assign(n + 1, vector<long long>(3, -1));
    memo[0][0] = memo[0][1] = memo[0][2] = 1;
    long long res = 0;
    for (int i = 0; i < 3; ++i){
        res = (res + rec(n, i))%mod;
    }
    cout << res << endl;
}