// 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

#define arrlen(x) (sizeof(x) / sizeof((x)[0]))

char str[100];
ul a[1000006];
ul *an = a + 3, *an2 = a + 1, *end = a + 1000005; 

int main() {
    
    *an2 = 1UL;
    while (an != end) {
        *(an++) = ((*(an - 2)) + (*(an - 3))) % MD;
    }
    
    int n = 0;
    int k = fread(str, sizeof(char), arrlen(str), stdin);
    str[k - 1]= 0;
    char *p = str;
    while (*p) {
        n = (n * 10) + (int)(*p++ - '0');
    }
    
    ul r = a[n + 4], t;
    
    *(p = str + 98) = '\n';
    while (r) {
        t = r / 10UL;
        *(--p) = '0' + (char)(r - 10UL * t);
        r = t;
    }
    
    fwrite(p, sizeof(char), str + 99 - p, stdout);
    
    return 0;
}