var a: array of integer;
n, i: integer;

function count(a:array of integer; b:integer) :integer;
var i, n:integer;
begin
n := 0;
for i:=1 to length(a) do if a[i]=b then n := n+1;
count := n;
end;


//var a :array of integer;
//n :integer;
begin
readln(n);
setlength(a, n+1);
for i:= 1 to n do readln(a[i]);
writeln();
for i:=1 to n do
begin
if count(a, a[i]) <= 3 then writeln(a[i]);
end;
readln();
end.