#include<stdio.h>
#include<stdlib.h>

void run(void){
  int n;
  scanf("%d",&n);

  const int mod=1000000007;

  int *ken=(int *)calloc(n+1,sizeof(int));
  int *kenken=(int *)calloc(n+1,sizeof(int));
  int *pa=(int *)calloc(n+1,sizeof(int));

  ken[1]=1;
  int i;
  for(i=2;i<=n;i++){
    ken[i]=pa[i-1];
    kenken[i]=ken[i-1];
    pa[i]=(ken[i-1]+kenken[i-1])%mod;
  }
  printf("%d\n",((ken[n]+kenken[n])%mod+pa[n])%mod);
  free(ken);
  free(kenken);
  free(pa);
  return;
}

int main(void){
  run();
  return 0;
}