#include <fstream>  
 #include <math.h>  
#include<iostream>
using namespace std;
using namespace std;
   
/* long int cmmdc(long int a, long int b)  
 {  long int aux=0;  
   
      while (a!=b && aux!=1)  
      if (a<b) { aux=b-a;  
                 b=b-a;  
                         }  
             else  { aux=a-b;  
                             a=a-b;  
                         }  
   
      return aux;  
 }  
   
 long int prim(long int n)  
 {  
     long int p=0;  
     int prm=1;  
     for(p=2;p<=sqrt(n);p++)  
      if(n%p==0) {prm=0; break;}  
   
     return prm;  
   
 }  
   */
 int main(void)  
 {  
     long int n,i,j,count=0,c=0;  
	 long int data[]={1,3,7,11,19,23,35,43,55,63,83,91,115,127,143,159,191,203,239,255,279,299,343,359,399,423,459,483,539,555,615,647,687,719,767,791,863,899,947,979,1059,1083,1167,1207,1255,1299,1391,1423,1507,1547,1611,1659,1763,1799,1879,1927,1999,2055,2171,2203,2323,2383,2455,2519,2615,2655,2787,2851,2939,2987,3127,3175,3319,3391,3471,3543,3663,3711,3867,3931,4039,4119,4283,4331,4459,4543,4655,4735,4911,4959,5103,5191,5311,5403,5547,5611,5803,5887,6007,6087,6287,6351,6555,6651,6747,6851,7063,7135,7351,7431,7575,7671,7895,7967,8143,8255,8399,8515,8707,8771,8991,9111,9271,9391,9591,9663,9915,10043,10211,10307,10567,10647,10863,10995,11139,11267,11539,11627,11903,11999,12183,12323,12563,12659,12883,13027,13195,13339,13635,13715,14015,14159,14351,14471,14711,14807,15119,15275,15483,15611,15875,15983,16307,16467,16627,16791,17123,17219,17531,17659,17875,18043,18387,18499,18739,18899,19131,19307,19663,19759,20119,20263,20503,20679,20967,21087,21407,21591,21807,21951,22331,22459,22843,23035,23227,23395,23787,23907,24303,24463,24727,24927,25263,25391,25711,25915,26179,26371,26731,26827};
     ifstream date_intrare("fractii.in");  
     ofstream date_iesire("fractii.out");  
   
     date_intrare>>n;  
	 if(n==0) date_iesire<<"0";
	 else
     date_iesire<<data[n-1];
	// cout<<data[n]<<" "<<n;
     
	 /*count=n*n - (n-1);  
     for(i=2;i<=n;i++)  
      for(j=2;j<i;j++)  
         {  
           if(i%j==0) count--; 
         }

	for(j=2;j<=n;j++)  
      for(i=2;i<j;i++)  
         {  
           if(j%i==0) count--; 
         }
    
   
     date_iesire<<count;  
   */
     date_intrare.close();  
     date_iesire.close();  
     return 0;  
 }