diff --git a/2019/4/ocaml.ml b/2019/4/ocaml.ml
new file mode 100644
index 0000000..cf5601f
--- /dev/null
+++ b/2019/4/ocaml.ml
@@ -0,0 +1,48 @@
+let start = 109165;;
+let finish = 576723;;
+
+let range start finish =
+	let rec generator curr fin acc =
+		if (curr=fin) then List.rev(fin::acc)
+		else generator (curr+1) fin (curr::acc)
+	in generator start finish [];;
+
+let domain = range 109165 576723;;
+
+let digits2list number =
+	let rec aux acc x =
+		if x <= 0 then acc
+		else aux ((x mod 10)::acc) (x/10)
+	in aux [] number;;
+
+let isNotDecreasing number =
+	let list = digits2list number
+	in fst (List.fold_left (fun (b,p) n -> if n<p then (false,n) else (b,n)) (true, (List.hd list)) (List.tl list));;
+
+let hasAnyPair number =
+	let list = digits2list number
+	in fst (List.fold_left (fun (b,p) n -> if p=n then (true,n) else (b,n)) (false, (List.hd list)) (List.tl list));;
+
+let predicate number = isNotDecreasing number && hasAnyPair number;;
+
+let filtered = List.filter (fun x -> predicate x) domain;;
+
+let result1 = List.length filtered;; (* part 1 result *)
+
+(* ====================== PART 2 ====================== *)
+
+let predicatePart2 number =
+	let list = List.rev(-1::digits2list number)
+	in let (_,_,comboList) = List.fold_left (fun (prev, count, acc) next -> 
+			if prev=next then (next, count+1, acc)
+			else (next, 1, count::acc)
+		) ((List.hd list), 1, []) (List.tl list)
+		in List.mem 2 comboList;;
+		
+let lol = predicatePart2 11010343;;	
+		
+		
+let filtered2 = List.filter (fun x -> predicatePart2 x) filtered;;
+
+let result2 = List.length filtered2;;
+