diff --git a/day_2.cpp b/day_2.cpp
index f332010..73c5fed 100644
--- a/day_2.cpp
+++ b/day_2.cpp
@@ -1,10 +1,10 @@
 #include <fstream>
 #include <iostream>
 
-bool is_invalid(long int id)
+bool is_invalid_part_1(long int id)
 {
 	std::string id_str = std::to_string(id);
-	for (int i = 0; i < id_str.size(); i++) {
+	for (int i = 1; i < id_str.size(); i++) {
 		if (id_str.substr(0, i) + id_str.substr(0, i) == id_str) {
 			return true;
 		}
@@ -12,26 +12,41 @@ bool is_invalid(long int id)
 	return false;
 }
 
+bool is_invalid_part_2(long int id)
+{
+	std::string id_str = std::to_string(id);
+	for (int repeat_length = 1; repeat_length < id_str.size(); repeat_length++) {
+		for (int repeat_count = 0; repeat_count < id_str.size() / repeat_length + 1; repeat_count++) {
+			std::string new_str;
+
+			for (int i = 0; i < repeat_count; i++) {
+				new_str += id_str.substr(0, repeat_length);
+			}
+
+			if (new_str == id_str) return true;
+		}
+	}
+	return false;
+}
+
 int main()
 {
 	std::ifstream file("input.txt");
 
-	long int invalid_sum = 0;
+	long int part_1_invalid_sum = 0, part_2_invalid_sum = 0;
 
 	std::string range;
 	while (getline(file, range, ',')) {
 		long int range_start, range_end;
 		sscanf(range.c_str(), "%ld-%ld", &range_start, &range_end);
 
-		std::cout << "Range " << range_start << "-" << range_end << ":";
+		std::cout << "Range " << range_start << "-" << range_end << std::endl;
 		for (long int i = range_start; i <= range_end; i++) {
-			if (is_invalid(i)) {
-				std::cout << " " << i;
-				invalid_sum += i;
-			}
+			if (is_invalid_part_1(i)) part_1_invalid_sum += i;
+			if (is_invalid_part_2(i)) part_2_invalid_sum += i;
 		}
-		std::cout << std::endl;
 	}
 
-	std::cout << "Sum of invalid IDs: " << invalid_sum << std::endl;
+	std::cout << std::endl;
+	std::cout << "Sum of invalid IDs:\n  Part 1: " << part_1_invalid_sum << "\n  Part 2: " << part_2_invalid_sum << std::endl;
 }