program zhou;
var
a,b,c,d:longint;
procedure ss(a:longint ;var d:longint);
begin
d:=1;
while a>=10 do
begin
d:=d+1;
a:=a mod  10;end;
end;
begin
for a:=2 to 1000 do
  begin
    c:=1;
    ss(a,d);
  for b:= 1 to d do
    c:=c*10;
    if ((a*a) mod c)=a
then write(a,' ')
end; readln
end.

可能有点错...
多少加点分~~~

program zhs (input,output);
  var
    i,j:longint;
  begin
    for i:=2 to 1000 do
      begin
        j:=i*i;
        if (j mod 10=i) or (j mod 100=i) or (j mod 1000=i) or
           (j mod 1000=i)
          then write(i:10)
      end;
    writeln
  end.

二楼的程序不错！