#include<fstream.h>
  ifstream fi;
  ofstream fo;
 int cmmdc(long x,long y)
 { while(x!=y)
   {if(x>y)x=x-y;
    else y=y-x;
   }
  return x;
 }
 main()
 {int mimp=0,mp=0,nr=0,n,i,j,d,k,q;
 int p[32000],imp[32000];
 fi.open("pairs.in");
  fo.open("pairs.out");
  fi>>n;k=1;q=1;
  for(i=1;i<=n;i++)
   {fi>>d;
    if(d%2==0){p[q]=d;mp++;q++;}
    else {imp[k]=d;mimp++;k++;}

   }
   for(i=1;i<=mp;i++)
     for(j=1;j<=mimp;j++)
      if(cmmdc(p[i],imp[j])==1)nr++;

   for(i=1;i<=mimp;i++)
    for(j=i+1;j<=mimp;j++)
      if(cmmdc(imp[i],imp[j])==1)nr++;

   fo<<nr;
   fi.close();
   fo.close();
 }