Thanks. I have seen the page of neerc.
Now I've got AC.
By the way, can you tell me some other online contest, like neerc.
Thanks once more.

> > Can you give me a test.
> > I can't find a test that my pro. run incorectly.
> > Thanks a lot.
> > Here's my pro.:
> >
> > const maxn=101;
> > var a,d:array[1..maxn,1..maxn] of byte;
> >     doi:array['('..']'] of char;
> >     st:string;
> >     n:integer;
> >
> > procedure in_data;
> > begin
> >    readln(st);
> >    n:=length(st);
> >    doi['(']:=')'; doi[')']:='(';
> >    doi['[']:=']'; doi[']']:='[';
> > end;
> >
> > procedure solve;
> > var i,j,k:integer;
> > begin
> >    fillchar(a,sizeof(a),0);
> >    for i:=1 to n do a[i,i]:=1;
> >
> >    for i:=1 to n-1 do
> >    for j:=i+1 to n do
> >    begin
> >       a[i,j]:=255;
> >       if (st[i]=doi[st[j]]) and (st[i] in ['(','[']) then
> >       if a[i+1,j-1]<a[i,j] then
> >       begin
> >          a[i,j]:=a[i+1,j-1];
> >          d[i,j]:=0;
> >       end;
> >
> >       for k:=i to j-1 do
> >       if a[i,k]+a[k+1,j]<a[i,j] then
>
> { you haven't defined  the value a[k+1,j] !!! }
>
> >       begin
> >          a[i,j]:=a[i,k]+a[k+1,j];
> >          d[i,j]:=k;
> >       end;
> >    end;
> > end;
> >
> > procedure out(i,j:integer);
> > begin
> >    if i>j then exit;
> >    if i=j then
> >    begin
> >       if st[i] in ['(','['] then write(st[i],doi[st[i]])
> >       else write(doi[st[i]],st[i]);
> >    end
> >    else if d[i,j]=0 then
> >    begin
> >       write(st[i]);
> >       if i+1<=j-1 then out(i+1,j-1);
> >       write(st[j]);
> >    end
> >    else
> >    begin
> >       out(i,d[i,j]);
> >       out(d[i,j]+1,j);
> >    end;
> > end;
> >
> > begin
> >    in_data;
> >    solve;
> >    out(1,n);
> >    writeln;
> > end.