program asdfghjkl;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var a:array[1..10000]of integer;
  n,i,s,k:integer;
  sa :real;
begin
  writeln('vvedit kilikist elementiv n');
  readln(n);
  for i:=1 to n do
  begin
  write('a[',i,']=');
  readln(a[i]);
  end;
  s:=0;
  k:=0;
  for i:=1 to n do
  if a[i]>0 then
  begin
  s:=s+a[i];
  k:=k+1;
  end;
  if k=0 then
  writeln(0)else
  begin
  sa:=s/k;
  writeln('sa=' ,sa:2:2);
  end;
  readln;
end.