var a:array[1..200] of integer;
i,n,s,dem:integer;
tb:real;
begin
write('Nhap so luong phan tu n = ');readln(n);
for i:=1 to n do
begin
write('Nhap phan tu thu ',i,' = ');readln(a[i]);
end;
for i:=1 to n do
if (a[i] mod 3 = 0) and (a[i] > 0) then
begin
s:=s+a[i];
dem:=dem+1;
end;
tb:=s/dem;
write('trung binh cac so duong chia het cho 3 la ',tb:10:2)
readln;
end.