{"trustable":true,"prependHtml":"\u003cstyle type\u003d\u0027text/css\u0027\u003e\n .input, .output {\n border: 1px solid #888888;\n }\n .output {\n margin-bottom: 1em;\n position: relative;\n top: -1px;\n }\n .output pre, .input pre {\n background-color: #EFEFEF;\n line-height: 1.25em;\n margin: 0;\n padding: 0.25em;\n }\n \u003c/style\u003e\n \u003clink rel\u003d\"stylesheet\" href\u003d\"//codeforces.org/s/96598/css/problem-statement.css\" type\u003d\"text/css\" /\u003e\u003cscript\u003e window.katexOptions \u003d { disable: true }; \u003c/script\u003e\n\u003cscript type\u003d\"text/x-mathjax-config\"\u003e\n MathJax.Hub.Config({\n tex2jax: {\n inlineMath: [[\u0027$$$\u0027,\u0027$$$\u0027], [\u0027$\u0027,\u0027$\u0027]],\n displayMath: [[\u0027$$$$$$\u0027,\u0027$$$$$$\u0027], [\u0027$$\u0027,\u0027$$\u0027]]\n }\n });\n\u003c/script\u003e\n\u003cscript type\u003d\"text/javascript\" async src\u003d\"https://mathjax.codeforces.org/MathJax.js?config\u003dTeX-AMS_HTML-full\"\u003e\u003c/script\u003e","sections":[{"title":"","value":{"format":"HTML","content":"\u003cp\u003eRikhail Mubinchik believes that the current definition of prime numbers is obsolete as they are too complex and unpredictable. A palindromic number is another matter. It is aesthetically pleasing, and it has a number of remarkable properties. Help Rikhail to convince the scientific community in this!\u003c/p\u003e\u003cp\u003eLet us remind you that a number is called \u003cspan class\u003d\"tex-font-style-it\"\u003eprime\u003c/span\u003e if it is integer larger than one, and is not divisible by any positive integer other than itself and one.\u003c/p\u003e\u003cp\u003eRikhail calls a number a \u003cspan class\u003d\"tex-font-style-it\"\u003epalindromic\u003c/span\u003e if it is integer, positive, and its decimal representation without leading zeros is a palindrome, i.e. reads the same from left to right and right to left.\u003c/p\u003e\u003cp\u003eOne problem with prime numbers is that there are too many of them. Let\u0027s introduce the following notation: \u003cspan class\u003d\"tex-span\"\u003eπ(\u003ci\u003en\u003c/i\u003e)\u003c/span\u003e\u0026nbsp;— the number of primes no larger than \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003erub\u003c/i\u003e(\u003ci\u003en\u003c/i\u003e)\u003c/span\u003e\u0026nbsp;— the number of palindromic numbers no larger than \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e. Rikhail wants to prove that there are a lot more primes than palindromic ones.\u003c/p\u003e\u003cp\u003eHe asked you to solve the following problem: for a given value of the coefficient \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e find the maximum \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003en\u003c/i\u003e\u003c/span\u003e, such that \u003cspan class\u003d\"tex-span\"\u003eπ(\u003ci\u003en\u003c/i\u003e) ≤ \u003ci\u003eA\u003c/i\u003e·\u003ci\u003erub\u003c/i\u003e(\u003ci\u003en\u003c/i\u003e)\u003c/span\u003e.\u003c/p\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cp\u003eThe input consists of two positive integers \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003ep\u003c/i\u003e\u003c/span\u003e, \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eq\u003c/i\u003e\u003c/span\u003e, the numerator and denominator of the fraction that is the value of \u003cspan class\u003d\"tex-span\"\u003e\u003ci\u003eA\u003c/i\u003e\u003c/span\u003e\u0026nbsp;(\u003cimg align\u003d\"middle\" class\u003d\"tex-formula\" src\u003d\"CDN_BASE_URL/8396f8a3a8d4ff3e5b66e4c0bf3f0b0d?v\u003d1714022560\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e,\u0026nbsp;\u003cimg align\u003d\"middle\" class\u003d\"tex-formula\" src\u003d\"CDN_BASE_URL/9daeefdb526244dd4c2771bea0834536?v\u003d1714022560\" style\u003d\"max-width: 100.0%;max-height: 100.0%;\"\u003e).\u003c/p\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cp\u003eIf such maximum number exists, then print it. Otherwise, print \u003cspan class\u003d\"tex-font-style-tt\"\u003e\"Palindromic tree is better than splay tree\"\u003c/span\u003e (without the quotes).\u003c/p\u003e"}},{"title":"Examples","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e1 1\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e40\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e1 42\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e1\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}},{"title":"","value":{"format":"HTML","content":"\u003ctable class\u003d\u0027vjudge_sample\u0027\u003e\n\u003cthead\u003e\n \u003ctr\u003e\n \u003cth\u003eInput\u003c/th\u003e\n \u003cth\u003eOutput\u003c/th\u003e\n \u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cpre\u003e6 4\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e172\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}