#include <iostream>
#include <cstring>
#include <algorithm>
#include <limits.h>
#include <cmath>
#include <time.h>
#include <functional>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
#define MOD1 1000000007;
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
/* ここからが本編 */
/*  */
ull dp[1000005];
// dp[i]はiがパーで終わる奴
void solve(int n)
{
  int i;
  dp[0] = 1; //便宜上
  dp[1] = 0;
  dp[2] = 1;
  dp[3] = 1;
  dp[4] = 1;
  for(i=5;i<n+1;i++) {
    dp[i] = (dp[i-2] + dp[i-3])%MOD1 ;
  }
}
int main(void)
{
  int test = 0;
  int i,j,k,l;
  int N;
  ull rep;
  cin >> N;
  solve(N);
  if(test) {
    for(i=0;i<N+1;i++) {
      printf("dp[%d] = %llu\n",i,dp[i]);
    }
  }
  if(N > 2) {
    rep = (dp[N] + dp[N-1] + dp[N-2]) %MOD1;
  }
  else {
    switch(N) {
    case 2: rep = 2;break;
    case 1: rep = 1;break;
    }
  }
  cout << rep << endl;
  return 0;
}