读取时

for i:=1 to m do

begin

readln(a,a);

d[a,a]:=1;

d[a,a]:=1;

end;

错最后一个点

读取时

for i:=1 to m do

begin

readln(x,y);

d[x,y]:=1;

d[y,x]:=1;

end;

AC~