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