#include<stdio.h>

int k,n,i,j,sol[200000];
char v[2000000];

int main(){

FILE *f=fopen("ciur.in","r");
fscanf(f,"%d",&n);
fclose(f);



  for(i=2;i<=n;i++){

   if(v[i]==0){
   k++;
   sol[k]=i;


     for(j=i;j<=n;j+=i){
     v[j]=1;
     }

   }


  }


FILE *g=fopen("ciur.out","w");

fprintf(g,"%d\n",k);


if(k<=1000){

  for(i=1;i<=k;i++){
  fprintf(g,"%d ",sol[i]);
  }

}

else{

  for(i=k-1000+1;i<=k;i++){
  fprintf(g,"%d ",sol[i]);
  }

}

fclose(g);

return 0;
}