This is my code.I think there is no problem,but I got WA#8.
Who can find the mistake for me?
Thanks very much.

program u1088;
 const d:array[0..30]of longint=
  (0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535,131071,
  262143,524287,1048575,2097151,4194303,8388607,16777215,33554431,67108863,
  134217727,268435455,536870911,1073741823);
 var f,h,hi,i,j,k:longint;
     p,l:array[1..2]of longint;{[1]d;[2]e; p:d; l:long; b:N-th}
     b:array[1..2]of longint;
procedure hs(i:longint;flag:boolean);
begin
 if flag then inc(hi);
 b[i]:=b[i] div 2;
end;
Begin
 read(l[1],l[2],f,p[1],p[2],h);
 for i:=1 to 2 do
  begin
   if (l[i]>f) or (p[i]>d[f]+1) then begin writeln('NO'); halt; end;
   b[i]:=p[i]+d[f];
   for j:=1 to l[i] do hs(i,false);
  end;
 if l[1]<l[2] then begin i:=1; j:=2; end
              else begin i:=2; j:=2; end;
 hi:=0;
 for k:=1 to l[j]-l[i] do hs(i,true);
 while b[1]<>b[2] do
  for i:=1 to 2 do hs(i,true);
 if hi<=h then writeln('YES')
          else writeln('NO');
End.

Maybe you should do: flag:=false(or true).
other way it will be random.