> 
> Program pku2234;
> 
> 
>  Var
>         
>         N           : Longint;
> 
> 
> 
> Procedure Work;
>  var
>         i,s     : Longint;
>           A     : Array [1..1000] of  longint;
> Begin
>   while not eof do
>   begin
>     read(N);
>     For i:=1 to N do
>     read(A[i]);
>     readln;
> 
>     s:=A[1];
>     for i:=2 to N  do s:=s xor A[i];
>     if s =0 then writeln('No') else Writeln('Yes');
> 
>   end;
> 
> End;
> 
> 
> 
> Begin
> 
>   Work;
> 
> End.

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