I don't no why my program get Wrong Answer???
There is my program:

const maxn = 100000;
var n,i,max,st: longint;
    a: array [0..maxn] of longint;
begin
     read(n);
     fillchar(a,Sizeof(a),0);
     a[0]:=0; a[1]:=1; st:=0;
     while n <> 0 do begin
           for i:=st to n do begin
               a[2*i]:=a[i]; a[2*i+1]:=a[i]+a[i+1]; end;
           max:=1;
           for i:=0 to n do if a[i] > a[max] then max:=i;
           write(a[max]); if n > st then st:=n;
           read(n);
     end;
end.

First, change write to writeln.
Then you'll get CRASH, because in a[2*i+1]:=.. i can be 100000, so,
you should have an array not [0..100000], but [0..200001].

Good luck!

Thank you!