// yukicoder My Practice
// author: Leonardone @ NEETSDKASU
#include <cstdio>
#include <iostream>

using namespace std;

typedef unsigned long ul;

const ul MD = 1000000007UL;

// 解説読後
// http://yukicoder.me/problems/882/editorial


ul a[1000006];

int main() {
    int n;
    cin >> n;
    
ul *an = a + 3, *an2 = a + 1, *enda = a + n + 5; 
    *an2 = 1UL;


    while (an != enda) {
        *(an++) = ((*(an - 3)) + (*(an - 4))) % MD;
    }

    cout << a[n + 4] << endl;
    

    return 0;
}