Вывести номер 1 и последнего кратного 5 pascal abc

Var
  a:array[1..10000] of integer;
  i, n, first, last:integer;
  fl: boolean;
begin
  Read(n);
  For i:= 1  to n do
    Read(a[i]);fl:=false;
  For i:= 1 to n do
    if (a[i] mod 5 = 0) then
      if (fl = false) then begin
                               fl:= true;
                               first := i;
                               last:= i;
                           end
                           else
                               last := i;
   Writeln('Первый -> ', first);
   Writeln('Последный -> ', last);
       
end.