Complete spectrum of V1057 Cyg obtained with the IRAM 30 m telescope. The selected lines are labeled with the name of the molecular species. The complete list of identified lines is provided in Table A.1, and zoom views of all lines are displayed in Fig. 2 and Figs. A.1–A.10 in Appendix A. The deep absorption features around 242–244 GHz and 258–259 GHz represent residual atmospheric absorption.