#include <bits/stdc++.h>

#define rep(i, a, b) for(int i = (a); i <= (b); i ++)
using std::cin, std::cout, std::cerr;
using ll = long long;

const ll P = 1e9 + 7;

void Solve() {
    int n; cin >> n;
    std::vector<ll> f(n + 1);
    f[0] = 1;
    rep(i, 1, n) {
        if(i >= 2) f[i] += f[i - 2];
        if(i >= 3) f[i] += f[i - 3];
        f[i] %= P;
    }

    ll ans = f[n] + f[n - 1] + (n >= 2 ? f[n - 2] : 0);
    ans %= P;
    cout << ans << '\n';
}

int main() {
    std::ios::sync_with_stdio(false);
    int T = 1;
    while(T --) {
        Solve();
    }
}