var
 s:string;
 i:byte;
 b:boolean;
begin
 write('N= ');
 readln(s);
 b:=true;
 i:=0;
 Repeat
  Inc(i);
  If s[i]<>s[Length(s)-i+1] then b:=false;
 Until (Not(b)) or (i=(Length(s) div 2));
 If b then Writeln('Yes!') else Writeln('No!');
 readln
end.