// yukicoder My Practice
// author: Leonardone @ NEETSDKASU
#include <stdio.h>

typedef unsigned long ul;

const ul MD = 1000000007UL;

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

ul a[1000006];
ul *an = a + 3, *an2 = a + 1, *end = a + 1000005; 

int main(void) {
    
    *an2 = 1UL;
    while (an != end) {
        *(an++) = ((*(an - 3)) + (*(an - 4))) % MD;
    }
    
    int n;
    scanf("%d", &n);
    
    printf("%lu\n", a[n + 4]);
    
    return 0;
}