{"trustable":true,"sections":[{"title":"","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eExperienced participants of the Ural Championship come to Yekaterinburg in\r\nadvance to get accustomed to the severe weather conditions, walk around the\r\ncity, and, of course, visit the “Limpopo” Water Park. Not many people know\r\nthat there is Plant No. 404 near the water park, and this plant is called\r\n“Error 404” by the locals. The plant is not easy to find indeed, and it is\r\nstill more difficult to learn what is happening there. Fortunately, one can\r\nwatch the plant from a nearby pedestrian bridge. Because of the seeming\r\nstillness and desolation of the plant, one may think that it is out of\r\noperation, but this is not so. The main work area of the plant is the repair of\r\naviation engines.\r\n\u003c/div\u003e\u003c/div\u003e\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eSome time ago the plant received an order to repair a broken gas turbine\r\nengine. It turned out that some blades were torn off, which resulted in an\r\nexcess load on the engine shaft. Experts at the plant have decided that the\r\nengine could be repaired quickly by removing some of the intact blades so that\r\nthe center of masses of the remaining blades would be on the rotation axis once\r\nagain. To keep the engine power as large as possible, a minimum number of\r\nblades should be removed. At least one blade must be left, otherwise the engine\r\nwould not work at all. The experts assert that when all the blades were intact\r\ntheir endpoints formed a regular \u003cnobr\u003e\u003ci\u003en\u003c/i\u003e-gon\u003c/nobr\u003e. Tell them which blades should be\r\nremoved.\r\n\u003c/div\u003e\u003c/div\u003e\u003cdiv class\u003d\"problem_centered_picture\"\u003e\u003cimg src\u003d\"CDN_BASE_URL/75bfbd8047f2a7228b8d63776d9e9685?v\u003d1716112249\" border\u003d\"0\" alt\u003d\"Problem illustration\"\u003e\u003c/div\u003e"}},{"title":"Input","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eThe first line contains the initial number of blades in the turbine \u003ci\u003en\u003c/i\u003e\r\nand the number of torn blades \u003ci\u003ek\u003c/i\u003e (\u003cnobr\u003e3 ≤ \u003ci\u003en\u003c/i\u003e ≤ 20000;\u003c/nobr\u003e \u003cnobr\u003e1 ≤ \u003ci\u003ek\u003c/i\u003e ≤ \u003ci\u003en\u003c/i\u003e − 1\u003c/nobr\u003e).\r\nThe integer \u003ci\u003en\u003c/i\u003e has at most two distinct prime divisors. The next line\r\ncontains \u003ci\u003ek\u003c/i\u003e integers, which are the numbers of the torn blades in ascending\r\norder. The blades are numbered from 1 to \u003ci\u003en\u003c/i\u003e clockwise.\r\n\u003c/div\u003e\u003c/div\u003e"}},{"title":"Output","value":{"format":"HTML","content":"\u003cdiv class\u003d\"problem_par\"\u003e\u003cdiv class\u003d\"problem_par_normal\"\u003eIn the first line output the minimum number of blades that should\r\nbe removed. In the second line output the numbers of these blades in any order\r\nseparated with a space. If several answers are possible, output any of them. If\r\nit is impossible to repair the engine by removing some of the blades,\r\noutput “−1”.\r\n\u003c/div\u003e\u003c/div\u003e"}},{"title":"Sample","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\u003e12 3\r\n3 4 12\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e2\r\n8 9\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cbr\u003e\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\u003e3 1\r\n1\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cpre\u003e-1\r\n\u003c/pre\u003e\u003c/td\u003e\n \u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n"}}]}