program Project1;
var
mes, mesK: string;
i: integer;
begin
Readln(mes);
for i := 1 to length(mes) do
begin
if mes[i] = mes[i + 1] then
mesK := ''
Else
mesK := mes[i];
Write(mesK);
End;
Readln;
end.
program Project1;
var
mes, mesK: string;
i: integer;
begin
Readln(mes);
for i := 1 to length(mes) do
begin
if mes[i] = mes[i + 1] then
mesK := ''
Else
mesK := mes[i];
Write(mesK);
End;
Readln;
end.