{"raw_statement":[{"iden":"problem statement","content":"Given is an integer $N$. Find the number of positive integers less than or equal to $N$ that have an odd number of digits (in base ten without leading zeros)."},{"iden":"constraints","content":"*   $1 \\leq N \\leq 10^5$"},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$"},{"iden":"sample input 1","content":"11"},{"iden":"sample output 1","content":"9\n\nAmong the positive integers less than or equal to $11$, nine integers have an odd number of digits: $1, 2, \\ldots, 9$."},{"iden":"sample input 2","content":"136"},{"iden":"sample output 2","content":"46\n\nIn addition to $1, 2, \\ldots, 9$, another $37$ integers also have an odd number of digits: $100, 101, \\ldots, 136$."},{"iden":"sample input 3","content":"100000"},{"iden":"sample output 3","content":"90909"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}