#include <bits/stdc++.h>
#define MOD 1000000007

using namespace std;

int N;
long long dp[1000001][4] = {{0}};

int main(void){
    
    cin >> N;
    
    int i, j, k, sum = 0;
    dp[1][1] = dp[2][2] = dp[3][3] = 1;
    for(i = 1; i <= N; ++i){
        for(j = 1; j <= 3; ++j){
            for(k = 1; k <= 3; ++k) if(j != k) sum += dp[i][k] % MOD;
            dp[i + j][j] += sum % MOD;
            sum = 0;
        }
    }
    
    cout << (dp[N][1] + dp[N][2] + dp[N][3]) % MOD << endl;
    
    return 0;
}