{"raw_statement":[{"iden":"problem statement","content":"Takahashi bought a piece of apple pie at ABC Confiserie. According to his memory, he paid $N$ yen (the currency of Japan) for it.\nThe consumption tax rate for foods in this shop is $8$ percent. That is, to buy an apple pie priced at $X$ yen before tax, you have to pay $X \\times 1.08$ yen (rounded down to the nearest integer).\nTakahashi forgot the price of his apple pie before tax, $X$, and wants to know it again. Write a program that takes $N$ as input and finds $X$. We assume $X$ is an integer.\nIf there are multiple possible values for $X$, find any one of them. Also, Takahashi's memory of $N$, the amount he paid, may be incorrect. If no value could be $X$, report that fact."},{"iden":"constraints","content":"*   $1 \\leq N \\leq 50000$\n*   $N$ is an integer."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$"},{"iden":"sample input 1","content":"432"},{"iden":"sample output 1","content":"400\n\nIf the apple pie is priced at $400$ yen before tax, you have to pay $400 \\times 1.08 = 432$ yen to buy one.  \nOtherwise, the amount you have to pay will not be $432$ yen."},{"iden":"sample input 2","content":"1079"},{"iden":"sample output 2","content":":(\n\nThere is no possible price before tax for which you have to pay $1079$ yen with tax."},{"iden":"sample input 3","content":"1001"},{"iden":"sample output 3","content":"927\n\nIf the apple pie is priced $927$ yen before tax, by rounding down $927 \\times 1.08 = 1001.16$, you have to pay $1001$ yen."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}