{"problem":{"name":"C. Cave Painting","description":{"content":"Imp is watching a documentary about cave painting. Some numbers, carved in chaotic order, immedi","description_type":"Markdown"},"platform":"Codeforces","limit":{"time_limit":1000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"CF922C"},"statements":[{"statement_type":"Markdown","content":"Imp is watching a documentary about cave painting.\n\nSome numbers, carved in chaotic order, immediately attracted his attention. Imp rapidly proposed a guess that they are the remainders of division of a number _n_ by all integers _i_ from 1 to _k_. Unfortunately, there are too many integers to analyze for Imp.\n\nImp wants you to check whether all these remainders are distinct. Formally, he wants to check, if all , 1 ≤ _i_ ≤ _k_, are distinct, i. e. there is no such pair (_i_, _j_) that:\n\n* 1 ≤ _i_ < _j_ ≤ _k_,\n* , where is the remainder of division _x_ by _y_.\n\n## Input\n\nThe only line contains two integers _n_, _k_ (1 ≤ _n_, _k_ ≤ 1018).\n\n## Output\n\nPrint \"_Yes_\", if all the remainders are distinct, and \"_No_\" otherwise.\n\nYou can print each letter in arbitrary case (lower or upper).\n\n[samples]\n\n## Note\n\nIn the first sample remainders modulo 1 and 4 coincide.","is_translate":false,"language":"English"},{"statement_type":"Markdown","content":"Imp 正在观看一部关于洞穴壁画的纪录片。\n\n一些以混乱顺序刻下的数字立即引起了他注意。Imp 快速推测这些数字是某个数 #cf_span[n] 除以从 #cf_span[1] 到 #cf_span[k] 的所有整数 #cf_span[i] 的余数。不幸的是，对于 Imp 来说，要分析的整数太多了。\n\nImp 希望你检查这些余数是否互不相同。形式化地说，他希望检查所有 #cf_span[1 ≤ i ≤ k] 的余数是否互不相同，即不存在一对 #cf_span[(i, j)] 满足：\n\n输入仅包含一行，包含两个整数 #cf_span[n], #cf_span[k] #cf_span[(1 ≤ n, k ≤ 10^{18})]。\n\n如果所有余数互不相同，则输出 \"_Yes_\"，否则输出 \"_No_\"。\n\n你可以以任意大小写形式输出每个字母。 \n\n在第一个样例中，对 #cf_span[1] 和 #cf_span[4] 取模的余数相同。\n\n## Input\n\n仅一行包含两个整数 #cf_span[n], #cf_span[k] #cf_span[(1 ≤ n, k ≤ 10^{18})]。\n\n## Output\n\n如果所有余数互不相同，则输出 \"_Yes_\"，否则输出 \"_No_\"。你可以以任意大小写形式输出每个字母。\n\n[samples]\n\n## Note\n\n在第一个样例中，对 #cf_span[1] 和 #cf_span[4] 取模的余数相同。","is_translate":true,"language":"Chinese"},{"statement_type":"Markdown","content":"**Definitions** \nLet $ n, k \\in \\mathbb{Z} $ with $ 1 \\leq n, k \\leq 10^{18} $. \nLet $ R_i = n \\bmod i $ for $ i \\in \\{1, 2, \\dots, k\\} $.\n\n**Objective** \nDetermine whether all remainders $ R_1, R_2, \\dots, R_k $ are distinct.","is_translate":false,"language":"Formal"}],"meta":{"iden":"CF922C","tags":["brute force","number theory"],"sample_group":[["4 4","No"],["5 3","Yes"]],"created_at":"2026-03-03 11:00:39"}}