#include <iostream>
#include <vector>

int main(){
    constexpr unsigned long long m = 1e9 + 7;
    unsigned int n;
    unsigned int i;
    std::vector<unsigned long long> dp = {1, 2, 2};
    std::cin >> n;
    for (i = 3; i < n; i++) {
        dp.push_back((dp[i - 2] + dp[i - 3]) % m);
    }
    std::cout << dp[n - 1];
}