GoDDamN

var
a:array[1..20] of integer;
i,j,k,n,a1,n3,a2:integer;
begin
readln(n);
readln(a1);
n3:=0;
For i:=2 to n do begin
If (a1 mod 3 <>0) then inc(n3);

readln(a2);
If (a2 mod 3 <>0) then k:=k+n3;

a1:=a2;
if n mod 2=0 then
j:=(n div 2)*(n-1)
else j:= (n div 2)*n
end;

writeln(j-k);

end.