#include <iostream>
using namespace std;
typedef long long int64;
int64 fib[1000000 + 1] = {1, 1, 2};
int64 md = 1000000007;
int main(void)
{
    int n;
    cin >> n;
    for(int i = 0; i <= n - 2; i++)
        fib[i + 3] = (fib[i] % md + fib[i + 1] % md) % md;
    cout << fib[n] << endl;
    return 0;
}