#include <stdio.h>

FILE *f,*g;
int n,i,j,how;

int cmmdc(int a,int b){
int r;
for(;;){
r=a%b;
a=b;
if(!r) return b;
b=r;
}
return b;
}


int mod=1;

int main(){
f=fopen("fractii.in","r");
g=fopen("fractii.out","w");
fscanf(f,"%d",&n);
for(i=1;i<=n;i++){
  if(!i%2) mod=2;
  else mod=1;
  for(j=1;j<=n;j+=mod)
      if(cmmdc(i,j)==1) how++;
}
fprintf(g,"%d\n",how);
fclose(g);
return  0;
}