#include <iostream>
#include <vector>
using namespace std;
using ll = long long int;
constexpr ll MOD = 1'000'000'007;

int main(){
    int n;
    cin >> n;
    vector<vector<ll>> memo(n+1, vector<ll>(3, 0));
    memo[0][0] = memo[1][0] = 1;
    for(int i = 2; i <= n; i++){
        for(int j = 0; j < 3; j++){
            for(int k = 0; k < 3; k++){
                if(i-j-1 < 0 || j == k) continue;
                memo[i][j] += memo[i-j-1][k];
                memo[i][j] %= MOD;
            }
        }
    }
    cout << (memo[n][0] + memo[n][1] + memo[n][2])%MOD << endl;
    return 0;
}