var
s: string;
Function CharOdd(C : String): String;
var i : integer;
begin
CharOdd := '';
i:=1;
while i <= Length(C) do
begin
CharOdd := CharOdd + C[i];
inc(i, 2);
end;
end;
begin
readln(s);
writeln(CharOdd(s));
end.
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