Although learning-based methods have shown significant performance improvement recently<cite> (Yang et al., 2015)</cite> , one of their main bottlenecks is the lack of appropriate training corpora. While previous works have employed data crawled from websites (Mihalcea and Strapparava, 2005; <cite>Yang et al., 2015)</cite> , Twitter (Cattle and Ma, 2016; Reyes et al., 2012) , sitcom subtitles (Bertero and Fung, 2016; Purandare and Litman, 2006) , or the New Yorker Cartoon Caption Contest (Radev et al., 2015; Shahaf et al., 2015) , these datasets are generally not released publicly.