Advent of code Day 6 part 1

 let input ='mgtgddtfdtffzvznvnrncrrbqqhlhhffzqqzpqqthhrhhfphfphhcppcddnwdnwwtmwttfvvthvvrrbvbmvmssrlslfslflppblllwrlrzlldwdllqblqbqbsscmsmwwffjpppnlnhllbblvbvsbbzvzrzzsmsjsddfpftfvtffgjjfzjfjqfqjfjsscvcccgttgtzgzmgmtmbbwzzjqzzdfzfmzmzfzwzvwvggqcqrrcwrcrzrccqcwwbgbqqwdqqzjzsjjwbjjssmmcfcbcddlhhtltmtlljffvjffhghmggmvvfgfqgfgppnpllmvmfvvzjjzrztztvvstsvvppqdpprjjmtmjtmjjdrdcrdccgsccnsccqsqzszqsqgqwggbhbllvclljrrlrqlljtjcjjlrlhrhjhjnnnpllwtwstttlnlqnlnmnqnpqpbqqbgbzzrhzrhzhrzhrzhzshhqvqgqgbbcqccqmcqccvgccrwrgwrgrdrhhbshbhwbhwbhhvthvttfrrqsstqssqmmpnpwpfpcffcdchhrsshrhggtcttmrrhvvjfvjvvclvllmqmvvhddrdjjhdhvhlvhlltlstltffbbqbwqbbbnsbnbwbssjwsjsfjjsjwwzttqzzsdspprlrblrltrrfrsfffwqwpwddddnqqtbtwwhwpwdwmmcrmrsmmwppjzpjpcpdpjpdpdqppmjjlqqjfqqhgqhhbddtccthhwjhhlfftvtppwzpwzpznpzpqpgqpgpnpdndnbnddqrrjdjwwdmmtnntvnnrhrfhfrfwfvwffmnfnlfldfdjjwgwqqwwsslrrvhhrqqsfqfllrmrqmrrbppwjppmlmggvppdhppspjjzljjrzzrlzrrlldllvlpvpfprfprrhdrdlllpqqfhqqhchzzzwpwjpjjgzzwqqtqdqbdbdgggbrgrzzznwwbvbnbpnbpprnrvvfvsscncrczcbchhjqhjjzrznndwnnvttmtthssgvvbvfvtvptpthhzggnjjhrjdqzjbtfpqdtwtmgnngqdzhdrfzqvcqggmcdbsdrdrmgqhmvfvdgbvrnlbhfsbpjhwgzfndqgcjdbpsffcslfcltsbclspdjhscqrncfrjrbjfzspccshtrdggjbhthrrhgnjvsptfnjvjvhhdjfbtfgpfgszhhbcvzplclrnsrpffpjhbthnfsfflqphhjjdpcfwzhfdpnsftrnfhrdhndlrnfrnvprtvnmgclzlrdjrzdcllvlwdlrcfbsgcbwcnbvjztzfsgcgqlmgcbsgwbbrmrcthfpvmbfvtbhqstccfntmphqpjwpbcdpnffqpszlnqdcqtfhvlvpgdpljvcschdtpvcswfzcbpqdhfjzzdjvgldspcvlnfnwffhjzdnbmjjtnrqlgnggsvdltnrpcfwqvphtsmrfzhflwjjbnpwlzhhmdnpqptgcjnrrgcnhwllqsbsjjvzmqsghlzvhdfbrnfhrqjswrpgcctsqvdwzgpqdssfmtgwvsznlbhsgppwdhhtjmscjfrjdgflwcrlbsfwrnvtnmcwpndhtttgqfvmvmfnwdrrvgmgdqlqvvlphwzgmwcphjvcfsqbbwttntmgvfmlmctggmtlwtmfsmczbgdvbsjstzgflnjplgrlhbbgldlchwmhclzbcwpqzlzbjzbplnvpbzjhmwfmrfnwlnsvpzhrgjdpqvnjtbfjfsvdqcfwdjftsmfqdrqllwlbnbmgtswrhbtbqlchznbgnphgntrtwbtmsjtphhqpbngwmmsdnsdqcctrsrzbrtpwtvhvqbrjldfldllpvspthdhdljfvjzcjsltwflscfqsrvzhgvzhqnnjwdwdtnsvgchzrnbzfscvsmrmqsqjmrjjdhtspbzpqtqqbfbzrddwqzwpqjbpbbbghlwmzhqvqdwwwwvltvvcpgzlwzvmqzfcgnjpjnpgsccvzpnzjwwnnjrcpbvwljfrjqzwsrvdmqwwfpldqcdwlchvggclmwnbhlrlzvsrtrqmzchqfqfhqfjgqsfvclnchdnnvdbqpcddnldggwrpbgrwwtssfndhrhnwtqmgrwpggntlqmfgbzjhwwsclvfmwgzzfrsccdfddntnlldpnwzhnzlssnnfbvjjhnrvclmphgfpvnwjzznbvgqnpljcrjpndgrlbdzsbfrrrfztbqcbphlppwcvhmrrmtrlvfjcddtznlmflrpsclgjpqczwrptfsccmdpzfvwnfsvshcnzrjrmstrslhgtrsmgplvcwptfqrgzgwhvtvrqlrjpcbztgtfwpnzqpmctvpdlgrtzzlsmgnftqvtvcmndspjqbdnmrttwhdrncsntntmrwjrqstdrptnhbqgtlqsdqfmbjtvgstndlvndqqsbqvcghwwjdzpszrsfpdzvnmnbzngczndtwtmprbzjdzbthslttzwwfptbphqwczsrqcbcbqnhbtcpjpbcqpjgjmhmfnggcbvctslpmqrpqzbcfrcgzmzpbpwzsjlrmpfzhgnnbqfrbslrfsthgtmsdfhzgdmjwwsgcdptssmbvffhlmfvwnmbpnzbvpsvnwsvsgrcmhpclwsbvtfqstnpzvgmgfcrmjhbccwcptssjhbfmzsqljjcrnnszvffzfwgcpnqrtjnqdltwnbglwlwpschvqwfdztvcwsqtwmgwccgsqbsvlwdhlnqphwtcmdpvvrqfwmlbptbvghvjntqbcsqjspwnmvdqcfbqzqchhhwqgdcmdhfvtzprscpshpbmzhwsznlpvzrwvmhtqsclzffgnvvrfbzmvqmnrrzjbmhdbspjprrmflgrwhnhcqpczchpnrnfjgdlnlrnzwnvjpmzgpfzspwmfnwcrrdczdhtnscmwqwqbcrdrsndpwbdvpgpbpsfzbmvjlsrdcgnwgrvmjnzlpnwtcrmnfcqgmlnhqbwlrnzlbdrnzfhnqddsfmnhnrrrdjgqprmgvrnhzrlccjthhfzdbltgrbrjpmbhvgrlwngdlfsljhfvwhvpmltdfnzwzcgzdpppnzcnpjttdgpzzqppnfzlmhrngbmcmshtgzbjllwstdbnmmwlrlllgfgshvcsjbpnggzrvvmvdqhjhvhmmpvrdqbrfpdtcdbqrvwhdrtqgftnwwzrcgzwmwjmdgmfswqwlgmvmvhscjmzshtbzmfmbqtbsjppzbczwcqpqhhqdggcntdchjgwsvfnzfqdzvhpnwbjhbqnldzbzmctcdqgjsmbqdzmmtjzvqzdqzsfpmncdmqlnpsrwcznbtzqtbcwwdqjftcdmmwdjdnwvpchffsmqmmwvqfgcnfhbjsttwnwppssmvrrhrbqwsncpfnbfggdqjwbgtvgtwsmlqbwzlghnzhjwphswjtbtptmhlzhvvrwqqcgwnmcqtcjlndwgjrpschhhsmrvvwtrjplwrtswhrjlgjhzgzrjhsbrjhtgnmfdvbjlntcrphsnmdcjzgwtvgldrfpcfgpzlgsfthdmpbnhmlsbnbqzpqvzzmvswbbnbtzvbsznqdgqlbbwzhjrzndltfgswtszsmmrhrcrcrcpgtqfcrmjrtflsbcbbmrsrfgnsrmbrpcvfpmqtmbrbbqtzrjntnvbvwjwqmwmcvmzccmwcnhrfpgghlqczcfszfhqgrdnfpnrrzpzbnjqjtvbglvqlhpstpzzcwrdgfhghqtsgzgsmgnpgvbsvsjtnwbvtqpcfdvhnjjvwjwglplthmghrwpmsgbdbfpvqsmsdvjgchlnlnczlzczqmjsnpgrgqgndwzdtlmmgzjpqvbqmcmhnhpqvpjjsftctwsrfmhrlctrvhczjbfsvqnshmchdsrmlrlqdnfsvhlblwghsdnrtwnpdtqgczmghqcmfzvsgqvrngjvbjsvnpzvpsplhvndvqpjjrtmrqscjrhvdmqcgwjmrgsdmgswgnbpdtgvvbrzrcwtvvwhpmcqwdtsmwwfgdpdrjsbvtbdvbhwftqznpssnsnjnclblslfgz';

    let result = -1;

    let solved = false;

    for(let i=0;i<input.length-4;i++)

    {

        if(!solved){

            let s = input.substring(i,(i+4));

            if(areUnique(s))

            {

                solved=true;

                result=(i+4);            

            }

        }

    }

    console.log(result);

}

function areUnique(str)

{

    return (new Set(str).size == str.length)

}