diff --git a/src/delf/etc/ln/Ln03.java b/src/delf/etc/ln/Ln03.java
new file mode 100644
index 0000000..41e9a38
--- /dev/null
+++ b/src/delf/etc/ln/Ln03.java
@@ -0,0 +1,74 @@
+package etc.ln;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author delf
+ */
+public class Ln03 {
+	public static void main(String[] args) {
+		System.out.println(new Ln03().solution("1110111100001111101111110000011111", 3));
+		System.out.println(new Ln03().solution("001100", 5));
+
+	}
+
+	public int solution(String road, int n) {
+		/* array로 표현된 road를 Interval의 List로 변환 */
+		List<Interval> list = new ArrayList<>();
+		char[] arr = road.toCharArray();
+		boolean isContinue = true;
+		int start = 0;
+		for (int i = 0; i < road.length(); i++) {
+			if (isContinue) { // 정상적인 도로였는데,
+				if (i == road.length() - 1 || arr[i + 1] == '0') { // 끊기면
+					list.add(new Interval(start, i)); // 거기까지가 새 구간
+					isContinue = false;
+				}
+				continue;
+			}
+			if (arr[i] == '1') { // 처음 정상도로를 만나면,
+				start = i; // 기록
+				isContinue = true;
+			}
+		}
+
+		int maxLength = 0;
+		int startIntervalIdx = 0;
+		do {
+			int tmpTotal = 0;
+			int brokenRoad = 0;
+			for (int i = startIntervalIdx; i < list.size() - 1; i++) { // 시작 구간을 하나씩 옮겨가면서 완성된 구간의 길이 중 최댓값 기록
+				Interval interval = list.get(i);
+				tmpTotal += interval.getLength();
+				if ((brokenRoad += interval.getMinimumDistanceTo(list.get(i + 1))) > n) { // 망가진 구간을 메워서 다음까지 연결 시킬 수 있는지 여부
+					break;
+				}
+			}
+			maxLength = Math.max(tmpTotal + n, maxLength); // 이번 루프에서 구간의 총 길이
+		} while (startIntervalIdx++ < list.size());
+
+		return maxLength;
+	}
+
+	// 정상도로 구간
+	class Interval {
+		private int start; // 정상적인 road가 시작되는 위차
+		private int end; // 정상적인 road가 끝나는 위치
+		private int length; // 구간의 길이
+
+		public Interval(int start, int end) {
+			this.start = start;
+			this.end = end;
+			length = end - start + 1;
+		}
+
+		public int getLength() {
+			return length;
+		}
+
+		public int getMinimumDistanceTo(Interval interval) {
+			return interval.start - this.end - 1;
+		}
+	}
+}
diff --git a/src/delf/etc/NV01.java b/src/delf/etc/ln/Ln06.java
similarity index 95%
rename from src/delf/etc/NV01.java
rename to src/delf/etc/ln/Ln06.java
index 7e34dc9..2b0ea6b 100644
--- a/src/delf/etc/NV01.java
+++ b/src/delf/etc/ln/Ln06.java
@@ -1,21 +1,21 @@
-package etc;
+package etc.ln;
 
 import java.util.*;
 
-public class NV01 {
+public class Ln06 {
 
 	public static void main(String[] args) throws CloneNotSupportedException {
-		System.out.println(Arrays.toString(new NV01().solution(
+		System.out.println(Arrays.toString(new Ln06().solution(
 				new String[]{"/", "/hello", "/hello/tmp", "/root", "/root/abcd", "/root/abcd/etc", "/root/abcd/hello"},
 				new String[]{"mkdir /root/tmp", "cp /hello /root/tmp", "rm /hello"}))
 		);
 
-		System.out.println(Arrays.toString(new NV01().solution(
+		System.out.println(Arrays.toString(new Ln06().solution(
 				new String[]{"/"},
 				new String[]{"mkdir /a", "mkdir /a/b", "mkdir /a/b/c", "cp /a/b /", "rm /a/b/c"}))
 		);
 
-		System.out.println(Arrays.toString(new NV01().solution(
+		System.out.println(Arrays.toString(new Ln06().solution(
 				new String[]{"/"},
 				new String[]{"mkdir /a", "mkdir /a/b", "mkdir /a/b/c", "cp /a/b /", "rm /a/b/c"}))
 		);
diff --git a/src/delf/programmers/Solution43105.java b/src/delf/programmers/Solution43105.java
new file mode 100644
index 0000000..11fd511
--- /dev/null
+++ b/src/delf/programmers/Solution43105.java
@@ -0,0 +1,29 @@
+package programmers;
+
+/**
+ * 정수 삼각형
+ * https://programmers.co.kr/learn/courses/30/lessons/43105
+ */
+public class Solution43105 {
+
+	public static void main(String[] args) {
+		System.out.println(new Solution43105().solution(new int[][]{{7}, {3, 8}, {8, 1, 0}, {2, 7, 4, 4}, {4, 5, 2, 6, 5}}));
+	}
+
+	public int solution(int[][] triangle) {
+		int answer;
+		int n = triangle.length;
+		int[][] dp = new int[n][n];
+
+		System.arraycopy(triangle[n - 1], 0, dp[n - 1], 0, n);
+
+		for (int i = n - 2; i >= 0; i--) {
+			for (int j = 0; j < i + 1; j++) {
+				dp[i][j] = Math.max(dp[i + 1][j], dp[i + 1][j + 1]) + triangle[i][j];
+			}
+		}
+		answer = dp[0][0];
+
+		return answer;
+	}
+}