#include<stdio.h>
long long n,x;
FILE *f=fopen("fractii.in","r");
FILE *g=fopen("fractii.out","w");
long v[]={2,3,5,7,9,13,15,19,21,25,31,33,39,43,45,49,55,61,63,69,73,75,81,85,91,99,103,105,109,111,115,129,133,139,141,151,153,159,165,169,175,181,183,193,195,199,201,213,225,229,231,235,241,243,253,259,265,271,273,279,283,285,295,309,313,315,319,333,339,349,351,355,361,369,375,381,385,391,399,403,411,421,423,433,435,441,445,451,459,463,465,469,481,489,493,501,505,511,523,525,543,549,559,565,571,573,579,589,595,601,603,609,615,619,621,633,643,645,649,655,661,663,675,679,685,693,703,711,721,729,735,741,745,753,759,763,771,775,789,799,811,813,823,825,829,831,841,855,859,861,865,879,883,885,889,909,913,921,931,939,943,949,955,969,973,979,985,993,999,1011,1015,1021,1023,1033,1035,1041,1051,1053,1063,1065,1071,1089,1093,1095,1099,1105,1111,1119,1125,1131,1153,1155,1165,1173,1183,1189,1195,1203,1215,1219,1225,1231,1233,1239,1251,1261,1279,1281,1285,1291,1293,1299,1303,1305,1309,1321,1323,1329,1363,1369,1375,1383,1401,1411,1425,1429,1431,1435,1441,1449,1453,1455,1461,1473,1483,1485,1489,1491,1495,1501,1513,1525,1533};
int verif(long y1,long y)
{

  for(long t=1;t<=200;t++)
    {if(y1%v[t]==0&y%v[t]==0)
	 return 0;
     if(v[t]>y1)
      return 1;
     }
   return 1;

}

void rez()
{

x=(n-1)*2+1;
 for(long i=2;i<n;i++)
   for(long j=i+1;j<=n;j++)
     {if(i==j+1)
        x+=2;
      else if((i%2==0)&&(j%2==0))
	     x+=0;
	     else if(verif(i,j))
		  x+=2;
     }

}

  


int main()
{ 
  fscanf(f,"%lld",&n);
   rez();
  
fprintf(g,"%lld",x);
 return 0;
}