diff --git a/src/input.txt b/src/input.txt
new file mode 100644
index 0000000..68bd997
--- /dev/null
+++ b/src/input.txt
@@ -0,0 +1 @@
+pjbjvjtjljplppjssvtvwtwptptztltbtrrjgrjrzrqrjrbrhbrhrlllbpbdbbzqqgsqshqssjjbsjbsbmbhhmchhrqrcqqbwbqwwqrrznnsbswwwdjwdwmmsvszzlbbgddbgdgfgttzjzrjzrjzzvrvqqgpqggtbgtgvvrhvhtvtjjbpjjfjhjbhbddbjjjmzmtmgmpgmmmljlnljjmpmbpmbmrrlhhlppdgdfgfbbqlbbtffjjgvvnpvpbpttqmmnhhgfgrrwhrrbnbznzccmbmvmmzszsvsbvbccsrslsjsbbtdtwtvttvpvzzvbzzwczwcczhzhwhjhjghgppgpgttdwdhwhphnppqmpqqhthcchdhmhnnbcnbcbbggbfblljttwsswspsggpjjzszcscsmcmdmnngzzhrzrbrhbhzbzvzgvgffnlnljlrrhchhsvhssmpmccncdnccgdgbglgtlggnllsvvpfvpfpbffsgglddjrrzzphhptprtppwrwffzllrbrmrpmpdmpdmpplpspcphcphhgmmqnmmvnmmdvmvsmmqjmmlmlbmlbmlltlptphpnncscbscbcggwhhgjgqjqmjmdjmdjdrrvgvvzlldgdnnvttmmpffdjjvvchcwwbhwbwzzlmlccrttcntccpcgccpgcpggdrrbtrthhlrrbqrrpspdsdldbldblbzbpbgggtngtgqqtwwdjjmmcrmcrcvclcddhllpzpdzzmccrtccfvffccfhccpscctbbbzqzvvllgwlgwgvwwjswjswsvvwhhvjvsjvjmmjhjrhrmrvrnrccmnmzzmdzzbtbvbqvvgzgcgvvvvlltvllbfbqqrppwhpwpffzddzdzwdzzrggmhmfhmhbbzjzsjzzhhjdhhdnndsnssnfffbmffwhwrhhmmbnnbrnrbrrtqtztnzzzzblbhbdhbbfmfqfmmsgszzvfzfmfwfnwfwggwngnqnwqnwqwvwqvwvdvrvjjfnjnmnfmmwzzltztjjqnnnmlmzlmmrcmclcqqhrhdhccdfdvfvccvtcvvdmmtmccwjjcbcrrjmrjrdrffgwwvbvlvsspwpsspzsschssmqsqmqmlqmmqgqfqcqjcjtthjttlddfvvwwjvvtpvvfsvffqnffznzqzszgzmmjttwztwzzhqqccqsqmqnmqqjhqhzhwhvhdddsndsdfftvffwlwnnmmdpmmnhhrqrrclcdlcddhcdcppgrprnpnptnpphgpbqfngdgzvgndwcgrwcsfmhzsvddhzbgjmvvdjjzswvgnpmvgdpwsgbgjzjpsrfdzdzjzzrpplbhsmgddqzjbdzdzltqqwqjzqvwfmcdppbdbprrwzhmnrqclzrnmdjnfbwmvdrwtpwvgscrqgpndqnzbjsbljcbthbpgdjdcdwfhpvjnbsfjdlrjldvvmtfdslrhlfwmvclqrljrqmmjgqfwmfgwdjzzptgcthvtgdswsqjrqvnzmtqldjjcqnfhtvbwhjqlvpptfwjrdpcwvzddgcjzvqbhtsnnnjqqmqlbgvqmvjhvvpbzcbdmhgmcjbfcccsvlzjztvjzrrlhtgwccdcgcptqlmdhmdhvqzfntbjqtsmvqgwsltqntgszllntrljfgfsghtbbcqrdgwqphmbqtzmjqccrgvqpqpchzjstdmmtvntwjqsbcqjgnhzlllcfbpgtgrhwwhqqdlgrlsbzbmchvjnsgpdnmqvtgwqjpgflqgfngjfcfwqzmvvgzmmhbgfnbzvzclwclqdcccgbrrzpwdtprgsvhbgsnbntgrvnzhrnzfzdmnlbnrbqvmjbwpgvjlhbcvsrlqmcsnlrvtfdwtvcbmlndgbctsnmtctjszlpddqmzbtphhhfznwbdfsgppmdmczmhmmrzpllfqqbgvlsrscpfgznhdhgrnnnvrchgvzlqbgvcfghjvlvrvpclfcshbmvglcfrjbzrbcjmjjrfgqthwfrqbgtjldmbnfwllspmwrvstvrltvrlvrtjvprgtgzjlrgclvjhqpfcwcdbdtzwdsdfrtsvtvgjmsszdfqlmhqqlzswjfndswlmhcrhglphvpnfjpbmggbwlmzjchpnrllbjpmgmzjjrqpqgsbrszqhdljcpnclvrvbntgtcdcmhtdhgslhpvdjpvrszfrjhsbvcvtfwvvgczprnpbhmnnlmctbtqdjspgvhvnhwvspwgnjvzllwlnjhfjwsslppmjbfbdnthcpzbcmnnbvhctgwgdvhvlrbltmdnlfcsncqgrmjprshdvvtvcccgzhszcjgczhmhtvmccjpchqshhdzjjhbfpzqdjszdhdvlmgctmwcjprwlsqbcqhlcrfdgnqzfdfvqslmqlppbsvbmjmfbrtdmpmtqvwvppcfzddjzhhzlrrnnhbrlhmzlqwftprfvctnfhfhfzrnrvggfqmqwcwszhtbfjncprgwcqbjlvtnrprlwwghswvprjmsbmqvwnnfggprndvshfvvwtrqjpwghgbppftgzhqjslfzhngwfsjnmjzdsjqgpmglwnjlcgmczgvndszrszcpnzqpbzjmgrfsbjlghwrbqsqdhlnhzsvsgbqhbcdffjlgrbdrrjvclzqpftlhdvvcrvlgvlpnjcqdcbdjtlwnldjhhhzrwsqlhlsztwrznfsszptlrhjmqwmnfwjtjwmmmtvwzhpmjgzgsscbddgvvhpcnhvnggzhbzvvjlmdftpbcsvtsttrvgghptmmcdclbdvmnsdntthfbdznbclwccnlzcvdwzrqgddjszvbdqcjppzrtpnrhfcvvwpjqczgqwzzzvzmlnlzqszvtllftthgwgftjzsndpzzcnqpcvmsdvvfrjdsvfclsqqhsjrrctfvdrlhfmhprjggdcmqrrbqtwnrllhhztvjgmzqszbvqfwsgllvhsvfrjffvdscwjzqlzlwdpgthddpgzjfdbdqpsnntwpslvsdpqfnsgcllszcjwvtqhwhpfrlfdgwrfmgfpjmvnstrmtfcvgwlqdfqvntltqtrmjjtwcthvwntqgvncssplnmvlnstlcphvlcmvjnstwldtntchcbmzmlzhgjfbrdlgzvqpgcndmfdnmcnwhmpdnpqstfddddcrpgrpfwfbzjqtnzwwqpzrqpmrjpfznrndfgwhtlvrcrphqfjzjbttwhgnsngqwvnsbvcqtjlmhvmnmnnmjcmlpnpgmrqsbmgljvsfqvrlljqzmzqqbgpvcrwdjmgsglssjswmnvtshhfqjhqmfmvcjwfpwsppgtrqsbhhcdljnjphnjszqpvdplbwzpwmmpwfhmhngtllzqvpmgdctmfqwwqjszssmjhwnrjdtmmvpdnwlqtcbpfcmwtbjmmsmmdpqgzdhsblgjmjbpzgqvqhnggtwmhztbbhlflllgwblncjjsngdgvsfdmsbsvlpnjjzqqbzhsqclmjnnmmwlpvtgwqmcgmrqdwdddlgbvhntbztbjnqhdlggnzwsdtdzprgddhtcttjrcpszgchtfwqjsdlnbntfwqpzpfsqrqjhthmcfszwtwcqwbvfzdnrrpmzjdrhsgmhfbsldvcrjdwvpqpszzlvbptljgvccqsdhhnztjpghbvhfptgplqdvldjzfthpspwvgljwnnndwrqzbrstnqbvrrcghssnrpvtrhmvcmbngwndzfswmgjwnnzqdcjhpthcgvthsnwqzrnzrvdjmctchhsbnrtvctzqfpcjhzmhnfjlqftbjztfbcppgmwvrzzrvlcpnpwwpvtcpdplrcfpgfqjtlfjtphhpcltwqcbqbznbtjrtdrpgtvzmgsclhpptrssqqbctdrftqzmwjmrmjtgmjmsnbnspjvcqpqnmgzgjrmfhghvsfsdqnbdjsbcpczsdswdcvhfzlgpzbtmztcnbpcvjnlcdmmlbtwzsfqtfnlrwjtwmgslcgptgbdsfwdhppvfwbbgdfdqtrbncbznmqtchzsdzlhlhjnnbpdvnnfjrdfbdqmvcb
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..6d9cb31 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,41 @@
-fn main() {
-    println!("Hello, world!");
+// https://adventofcode.com/2022/day/6
+
+const DATA: &'static str = include_str!("input.txt");
+
+fn has_duplicates(slice: &[char]) -> bool
+{
+    (1..slice.len()).any(|i| slice[i..].contains(&slice[i - 1]))
+}
+
+fn part1()
+{
+    let mut last_char = 0usize;
+
+    let mut buffer: Vec<char> = Vec::with_capacity(4);
+
+    for c in DATA.chars()
+    {
+        last_char += 1;
+
+        if buffer.len() == 4
+        {
+            buffer.remove(0);
+        }
+
+        buffer.push(c);
+
+        if last_char < 4 {
+            continue;
+        }
+
+        if !has_duplicates(buffer.as_slice())
+        {
+            println!("First start-of-packet marker at {}", last_char);
+            break;
+        }
+    }
+}
+
+fn main() {
+    part1();
 }