#include <atcoder/all>
using namespace std;
using mint = atcoder::modint1000000007;

int main(){
    int n;
    cin >> n;
    vector<array<mint,3>> dp(n + 1);
    dp[0][0] = 1;
    for(int i = 0; i < n; i++){
        for(int j = 0; j < 3; j++){
            if(j < 2)dp[i + 1][j + 1] += dp[i][j];
            if(j >= 1)dp[i + 1][0] += dp[i][j];
        }
    }
    cout << accumulate(dp[n].begin(), dp[n].end(), mint(0)).val() << '\n';
}