program pairs;
type vector=array [1..100000] of longint;
var v:vector;
i,j,nr,n:longint;
f:text;

function cmmdc(a,b:longint):longint;
begin
while a<>b do
        if a>b then
  	        a:=a-b
        else
                b:=b-a;
cmmdc:=a
end;

begin
assign(f,'pairs.in'); reset(f);
readln(f,n);
for i:=1 to n do
        readln(f,v[i]);
close(f);
nr:=0;
for i:=1 to n-1 do
        for j:=i+1 to n do
                if not ((v[i] mod 2=0) and (v[j] mod 2=0))then
                if cmmdc(v[i],v[j])=1 then
                        nr:=nr+1;
assign(f,'pairs.out'); rewrite(f);
writeln(f,nr);
close(f)
end.