Var f,g:Text;
    aux:char;
    n:String;
    i,p,j:Longint;

Begin

Assign(f,'ordine.in'); ReSet(f);
Assign(g,'ordine.out'); ReWrite(g);

readln(f,n);
p:=length(n);

for i:=1 to p-1 do
    for j:=i+1 to p do
        if (n[i]>n[j])and(n[i]<>n[j-1])and(n[i]<>n[j+1])and(n[j]<>n[i-1])and(n[j]<>n[i+1]) then begin
           aux:=n[i];
           n[i]:=n[j];
           n[j]:=aux;
           end;

WriteLn(g,n);

Close(f);
Close(g);

End.