studying room in the school or to a library to study instead of going home. This is called "yaja", which literally means "evening self-study". They do not need to go home to eat dinner since most schools provide paid dinner for students. After finishing yaja (which usually ends at 11:00 pm, but later than 12:00 am at some schools), they return home after studying, then usually return to specialty study schools (hagwon) often until 3am, from Monday to Friday. In addition, they often study on weekends. The yaja (야자, 야간자율학습, night self study) had not been truly "self" study for more than 30 years; all high school students were forced to do it. From the 2010s, the Ministry of Education has encouraged high schools to free students of yaja and to allow them to do it whenever they want. Many standard public high schools near Seoul are now no longer forcing students do it. But private high schools, special-purpose high schools (such as science high schools and foreign language high schools), or normal schools far from Seoul are still forcing students to do yaja. A common saying in Korea is: "If you sleep three hours each night, you may get into a top 'SKY university' (Seoul National University, Korea University, and Yonsei University). If you sleep four hours each night, you may get into another university. If you sleep five or more hours each night, especially in your last year of high school, forget about getting into any university." Accordingly, many high school students in their final year do not have any free time for holidays, birthdays or vacations before the CSATs (College Scholastic Ability Test, Korean: 수능, Suneung), which are university entrance exams held by the Ministry of Education. Surprisingly, some high school students are offered chances to travel with family to enjoy fun and relaxing vacations, but these offers are often refused on the first suggestion by the students themselves, and increasingly on later additional trips if any, due to peer influences and a fear of "falling behind" in classes. Many high school students seem to prefer staying with friends and studying, rather than taking a break. Truancy is extremely rare in Korea. Rebellious students will often stay in class and use smartphones connected to the internet to chat with friends behind the teacher's back during classes, which usually get them in trouble if caught. High schools in