var
  st:string;
  i,j:byte;
begin
  readln(st);
    j:=length(st);
    i:=1;
    while (j>i) and (st[i]=st[j]) do begin
    i:=i+1;
    j:=j-1;
  end;
  if j<=i then writeln('yes')
          else writeln('no');
end.
一直WA啊，输出短少QAQ求救

miss this!!!!

var

..............

begin

 

while not eof do begin

...................

.................

.................

end;

end.