#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
const int MOD = (int)1e9 + 7;

int main() {
    int n; cin >> n;
    int ken1 = 1, ken2 = 0, pa = 0;
    while (--n) {
        int _ken1 = ken1, _ken2 = ken2, _pa = pa;
        ken1 = _pa;
        ken2 = _ken1;
        (pa = _ken1 + _ken2) %= MOD;
    }
    cout << (ken1 + ken2 + pa) % MOD << endl;
    return 0;
}