为啥通不过最后三个节点

var b:array[1..1000000]of integer;m,n,i,j,x,y,z:integer;
function gjd(x:integer):integer;
 begin
  if b[x]=x then exit(x);
  b[x]:=gjd(b[x]);
  gjd:=b[x];
 end;
procedure hb(x,y:integer);
 begin
  x:=gjd(x);
  y:=gjd(y);
  b[x]:=y;
 end;
procedure sc(x,y:integer);
 begin
  if gjd(x)=gjd(y) then writeln('Y') else writeln('N');
 end;
 begin
  readln(n,m);
  for i:=1 to n do 
  b[i]:=i;
  for i:=1 to m do
   begin
    read(z,x,y);
    if z=1 then hb(x,y);
    if z=2 then sc(x,y);
   end;
end.