#include <cstdio>
#define MAX 30000

int main(void)
{
  char sieb[MAX];
  for (int i=0; i< MAX; ++i)
    sieb[i] = 0;
  FILE *fInput;
  fInput = fopen("assist.in","r");
  int llPos=2, count = 0, pos, count2;

  while (llPos < MAX)
  {
    //printf("%i ",sieb[llPos]);
    if (sieb[llPos] != 0)
    {
      ++llPos;
      continue;
    }
    sieb[llPos] = 1;
    for (int i=2*llPos; i < MAX; i+=llPos)
      sieb[i]=-1;
    ++count; 
    ++llPos;
  }

 NEXT:
 
  /*for (int i=0;i<100;++i)
    if(sieb[i] == 1)
    printf("%i %d\n",i,sieb[i]);goto END;*/
  fscanf(fInput,"%i",&count);
  //printf("%d ",count);
  
  pos = 1;count2=0;
  if (count==0)
    goto END;
  do
  {
    do
    {
      ++pos;// printf("%d %i\n",pos,sieb[pos]);
    } while(sieb[pos]!=1);
    ++count2;
  }while(count2<count);
  printf("%d\n",pos);
  goto NEXT;
END:
  return 0;
}