{"raw_statement":[{"iden":"problem statement","content":"There are $N$ students in a school.\nWe will divide these students into some groups, and in each group they will discuss some themes.\nYou think that groups consisting of two or less students cannot have an effective discussion, so you want to have as many groups consisting of three or more students as possible.\nDivide the students so that the number of groups consisting of three or more students is maximized."},{"iden":"constraints","content":"*   $1 \\leq N \\leq 1000$\n*   All input values are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$"},{"iden":"sample input 1","content":"8"},{"iden":"sample output 1","content":"2\n\nFor example, you can form a group of three students and another of five students."},{"iden":"sample input 2","content":"2"},{"iden":"sample output 2","content":"0\n\nSometimes you cannot form any group consisting of three or more students, regardless of how you divide the students."},{"iden":"sample input 3","content":"9"},{"iden":"sample output 3","content":"3"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}