var t:array[1..10000] of longint;
    a,b,n,i,j,k:longint;
    f,g:text;
begin
assign(f,'pairs.in');
reset(f);
assign(g,'pairs.out');
rewrite(g);
k:=0;
read(f,n);
for i:=1 to n do
read(f,t[i]);
for i:=1 to n-1 do begin
    for j:=i+1 to n do begin
    a:=t[i];
    b:=t[j];
    while a<>b do
               if a>b then a:=a-b
                      else b:=b-a;
    if a=1 then inc(k);
                       end;
                     end;
write(g,k);
close(f);
close(g);
end.