#include "stdio.h"
#include "stdlib.h"
#include "memory.h"

int main()
{
  int x, c,d,e;
  FILE *in;
  char sLine[512];
  in = fopen("assist.in", "rt");
  int v[34000];
  int lastx;
lastx = 0;
     for(int i=0;i<34000;i++) v[i] = i+2;
  while(!feof(in))
  {
     for(unsigned int i=0;i<sizeof(sLine);i++) sLine[i] = 0;
     fgets(sLine, sizeof(sLine), in);
     if(sLine[0]=='0') break;
 

     x = atoi(sLine);
     c = 0;
     for(int i=0;i<x-lastx;i++)
     {
        for(int j=0;j<34000;j++)
        {
           c = v[j];
           d = j;
           if(c!=0) break;
        }
        e = 0;
        for(int j=d+1;j<34000;j++)
        { 
          if(v[j]!=0)
          { e++;
            if(e%c==0) v[j]=0;
          }
        }
        v[d] = 0;
     }
    printf("%i\n", c);
    lastx = x;
  }


  fclose(in);  
  return 0;
}