面倒だ
It's such a bother.

A: You have to attend every class, right?
B: Yeah, it's such a bother.
A: 授業に出なくちゃいけないんでしょ？
B: そう、面倒くさいなあ。

★a bother は「厄介なもの」「悩みの種」という意味。