why? my program compile error???
my program run on FREEPASCAL is correct.
please help me!!!!

program ural1039;
  type
    n1=record
            ld,rd,p,d:integer;
          end;
  var
    tr:array[1..6000] of n1;
    v:array[1..6000] of boolean;
    f,g:array[1..6000] of longint;
    i,n,l,k,temp,root:integer;
  function max(x,y:longint):longint;
    begin
      max:=x;
      if max<y then max:=y;
    end;
  procedure treedp(i1:integer);
    var
      sum1,sum2:longint;
      t:integer;
    begin
      if v[i1] then exit;
      sum1:=tr[i1].d;
      sum2:=0;
      treedp(tr[i1].ld);
      sum1:=sum1+g[tr[i1].ld];
      sum2:=sum2+max(f[tr[i1].ld],g[tr[i1].ld]);
      t:=tr[tr[i1].ld].rd;
      while t<>0 do
        begin
          treedp(t);
          sum1:=sum1+g[t];
          sum2:=sum2+max(f[t],g[t]);
          t:=tr[t].rd;
        end;

      f[i1]:=sum1;
      g[i1]:=sum2;
      v[i1]:=true;
    end;
  begin
    readln(n);
    for i:=1 to n do
      begin
        f[i]:=0;
        g[i]:=0;
        v[i]:=false;
        tr[i].ld:=0;
        tr[i].rd:=0;
        tr[i].p:=0;
        tr[i].d:=0;
      end;
    for i:=1 to n do
      readln(tr[i].d);
    readln(l,k);
    repeat
      tr[l].p:=k;
      if tr[k].ld=0 then tr[k].ld:=l
                      else begin
                             temp:=tr[k].ld;
                             while tr[temp].rd<>0 do
                               temp:=tr[temp].rd;
                             tr[temp].rd:=l;
                           end;
      readln(l,k);
    until(l=0) and (k=0);
    for i:=1 to n do
      if tr[i].p=0 then begin
                            root:=i;
                            break;
                          end;
    for i:=1 to n do
      if tr[i].ld=0 then
        begin
          f[i]:=tr[i].d;
          g[i]:=0;
          v[i]:=true;
        end;
    treedp(root);
    writeln(max(f[root],g[root]));
  end.