const input::String = "sbpbwwrlwrwggscsfcsshsvhshphttzctztfflddvbvcbcvbcbnbrrstsspsvpvllncccqssqdssnsmshmshhtssbzzlplffzppddmhhwnhntnjtnjtnnqggjdgjdjrjffsdfsfbsffhtthwwfssqpspllcvcdvvfvfzfbzzgpglpgpmppfsfdfbfvvfjfsjjvqqbvqbvqbvvlvglvglvljvjzvvqcvqcqjcqqpddqbqcqrqmmvnvbnnfqnncznccqjcqqjzzwlltrrmmlwlllbjlblzlddfdmmscmsspfssqggbsbsjjdqdqgqgqbqdqrqlrrltttghthrtrwrdrnrfnfvftvtsvtvwtvwttvqtvtccqtqmqggwhhhlzhhrwwbwqwbbfrrmddwhdwdnwdwbdwwsswtwnnvvdggbbtwbbwllgffqpffpgpgmpmmjqqmpmffjgfgrffdzzspzptzzdszszbsbsbsvsbbhsbsbddnhhrqqcwwblbwlwnnthtsshmshmhgmgqgjqqpccfvcvbbbnllgmlgmmbnmnlmlzlffrrrgssmcmddnpdndtntrrqdqldldbbtppvddgndnwwctwccpbpffngnsgshggphggtssgngtnthtllzflzflzfzrfftgtstppghgnnpggrdgdnnswwccljlflwwgzgcgrrhssbwbllblnlvlddsffgrrnbbmsmmmhjmjvmjvmjmqqpdqppltlflmfmssqcqsqvsvsggpglplslggqtggmsmmmgffrccrvvsdvdvfddprdprrwjrjcjjmlmrmqmggqgdqdwdsdwwwgfwfddrcdcvcmmjbbmrrhlrrwcwvcclttwbwttgffnmnjmjdmmmlqmqrrlblplccdbcbwcbcpphpqpqlqrllqwwjsjgjbjqbbmcmzmrrqtrqqmcmmnjmjbbtnnbbjdjzzvbzvzjzdjzjrzzfzfbbmnmdnnzppmbpbhbdbvvqnqqnqrnrzrhhrddbqdqpqqwgwlglplglslhhpjpdjdjgddnppmvppjddczccgsccdsccbcvczccnbnmmsnsmmrwmwbmbbcpbbwbppzggdnnnzmnzzvrvcrvcvcrvrnrzzqzmzttjhhnffqggnqqwzwfzfwzwfwcwnccwgcwgcgqcgqcggzgwgfwgfffjttjddwswqqnttqwqsqhhcmchcscbbnwnlwlrlppqnnwjnjtntrtdtbbmzzrmzrzvrzvrzzwqwqllccnffvmmfmvmzzfttnnzttrbttdvvhdhzhzhvzzfsfszsvsttrqqdlldflfjjnqjjbhhqhzhcchppzsznntdntdddqqwjqjqmmgnnhrhjhnjnznwwdpplzzfzztbzzbmzmbbgjgtjtqjqpqhqgqhhtztpzpmzmjmhhjwwjsspbssvdsvsgvssghgvglgtltgllmhmtmhttfgglwgllpvpgpspzzhnnzcnzzldzdmzmlzzwtwhhlfhhvthhjdjsdsmddgzzsjjnznjnmjjgdgtdtzdtdvtddzwzgwwqvqccwrrrvddbtdbbshbhssnvsnvssswcwjcjlltvvltvvdsdqdsswlwttzfzhzjjgjsgjgttbccsvcscllbfbzzwwwznwwtzwzjzwjjgqjqrjrdjrddzsznsznzpzszhzzspzzbzrzhhsbspsqpqqqpddhdcdldttlccjrjsrsfftfdfrrtntpnpsnnwjnwnznpzzlqqlmqlmmcddlqqzssglsglssprmnvltqhslvqmvszjtvtwqjcdngjmftnhwvjdvtwwhtnsdmvjdspnhnlmjgnmwlspcvpdmlsrnbbzlmwwrslssmcbggmfvgzsnpnlnzdqsbhcfjdccrspnzfmhbvwstvccvqqjlwhpnlrrwszjnrtdfzwrwlzwvdvbzbvltdpfwrjlslmrctwvbbvdrctgtgwtwpjjghhvdsqhplfrsjqlgsrbfgwdjlzdpdljtvjmpwqqbghndqnvjhngtpnpvzfbtchncwdqjhmzjlpdggbdcqrfjlwvczvpspljqmpgtrsvwwhqncfvfrwbnvsfjqlsjdlrqzmlqjgcpghhgzfhjcglllnhtmchrrptbzhqnfntgqbfstrvpsqsvqvcvpgjnchbvmgtgzqfrqcjrvldzghdfrvllrtfcwnsmmgdrcbjmdqgbfwmpwhfjmnbqrbvqvnmjlqtsjqvhzpdsgbjpjngmzbgnznvjqprfvwzjrfrwfdqrtlcgqqlvrzwmqwjbdvprvpwvdcrfdrcttnmnvjfrsrrmjgfjdmpdpnfsrwnprtdpvdmdwssvjrqtlcvpgrqgqqqffvvssbmghzjrzrzlcrnfjtdbvwsjzfvcrsmgqbcrdrjwdwbltffwbgjwtgtdblmlhvhlcpgdmpcztmpmgjghqpwzwtpnmnmgnqqrrtwczgmgtdbgdqtpnlbnzhshsfzsmrztffrmlsgqcprbjpqwjlqgwvctpmpshgzbzsjgqhzvsrjfwplvjbvltrlfldvsmlppcmsfrbbctggmqmjnhppstzrcfjtdgfwrrnmlvjphwtlqtjqcntjtzvgjtwvthjfbgpwhlrzdqncmggvgthmgjvrbnzbndsldnlcgtcqbqdnnbnqhvtpfnrclttfwcpnqscjbzdvbqrrsbzpdfhjllbjwsltjpmdnbrrzvhvzzqnlbglsjrnjbqffnnzmldfvtvmldfsztrnpcjgblsdhzfzmfqzlfrtslglhfvszppptjnjqcdmjcwqmfzhnqbfhslwhvtjfvcftzsphvghvtjjswpwghnfngmzddbwwqddsphvhcrwtthsjfswfqbvdsqghmrspdldfqmchnnrcdvjsclcnlsncsplchvzrwqbtvvqlqspftrwmjcbgpzbsmnfccbzgnhqsfjgmmsqsscdscfjbrmmtjbsphhlrlsgbllrptqrcgnqchzfddjwlldsbpcnzfbspfpchclqfbbtjpmtmtjthcdvwhrtqbgmgldcgcnmmhtbnqpzzcwlrscbzcqjzgztwjrnbmsnqtcllznlctzrntftspmnvhtfwbljnmrwsstvbmwclqrfpmwvjphrwddzdwtlfcvzlvqdmzhnvslfnfjhvdndlgbvvzbztpwvqzbzsbtqpqfmgqfgpzctfrqfjwmsnmlfqbgrlmncntcbshjhdcbqnvznhtcgcmmhnsbwpzbvtqbntwgflhjgmvvfhdbwfqmnfjlzdvvnpmvjrdfdnrhpbtllhbtbswwvrbwjgnqpbgnfrjtvbczbpmrcbwdlhztzssnwshjmmcqchptrtchrqncdgdtmwrlnmmwqlzqswwwvpngvwcphgnzrhpprjnbldscvwlqdjwnhjrnscdwlnhnsbwgzjtgvzdgqcjcgvrdhntszhdnjsbbrfphlmdlldjdslbjnnsfbmcnvtlczmtnhrwblnbrdptcpmsbwqptgmwzsqnmmchwnnrvrlfsrglfzzqbnzmpdtnhhbmfqvsrsdsctvhqwfgbtvhbbrsrqmrvvplrnbfnbdmrvzpgctdtglndhcqnllvvcppgfbwjrpqcbghlqdbmpzwrqpmvwddqgthlmzmdsvzdfsmgzltbsvphctzgjsmqvgjlsbgnvmgprbcsfhgrtbwtnnrsqcwfzrhlgjcwcfrjhffrvrvtnpczvwvjnnhfdgcppnnjjpttptcbmdqvgdbhdmlqgcqsrnbcrbtcgzbvgmhbnwzsgnwzbhdqqmvtpssvlvsttgnmcclqnjcgjnvtdggrcwsgbpjljgzgtllsnfvfshtbbpwrjhzvzswlfdvhbpngvgddcmhbzqcvnjhfsqpnvvsdvdtmqlqpzcgsnwlflnqprbqnwdqchjvsptbtrvtzvhrmrvznfpzmcsgnqtdvghhzwrrwvqwrztvdbjjtfchpftdcbthpfdczwchpptwzdpswvbhppdphgvpfzhprpqtnprgfmdnqrbrdlclcmhrdfrcdhwpcqhnbwmhrrgnctpvsqmphcwwvlmslszhdz";

function find_marker(s::String; n=4)::Int
    i = n;
    L = length(s)::Int;
    while i <= L
        dup = false;
        for Ref = i:-1:(i-(n-2))
            for Cmp = (Ref-1):-1:(i-(n-1))
                if s[Ref] == s[Cmp]
                    i += Cmp - (i-n);
                    dup = true;
                    break;  # To do: optimize
                end
            end
        end
        if !dup
            return i;
        end
    end
    return -1;
end

println(find_marker(input; n=4));
println(find_marker(input; n=14));