diff --git a/InSange/BFS/18352.cpp b/InSange/BFS/18352.cpp
new file mode 100644
index 0000000..defc4c1
--- /dev/null
+++ b/InSange/BFS/18352.cpp
@@ -0,0 +1,143 @@
+//#include <iostream>
+//#include <queue>
+//#include <vector>
+//
+//using namespace std;
+//
+//int N, M, K, X, a, b, minDist;
+//deque<deque<int>> town;
+//queue<int> q;
+//vector<int> dist;
+//vector<int> answer;
+//
+//void Solve()
+//{
+//	cin >> N >> M >> K >> X;
+//	N++;
+//	town.assign(N, deque<int>());
+//	dist.assign(N, -1);
+//
+//	for (int i = 0; i < M; i++)
+//	{
+//		cin >> a >> b;
+//
+//		town[a].push_back(b);
+//	}
+//
+//	minDist = -1;
+//	q.push(X);
+//	dist[X] = 0;
+//
+//	while (!q.empty())
+//	{
+//		int cur = q.front();
+//		q.pop();
+//
+//		for (const int& val : town[cur])
+//		{
+//			if (dist[val] != -1) continue;
+//			q.push(val);
+//			dist[val] = dist[cur] + 1;
+//			minDist = max(minDist, dist[val]);
+//		}
+//	}
+//
+//	for (int i = 0; i < dist.size(); i++)
+//	{
+//		if (dist[i] == K) answer.push_back(i);
+//	}
+//
+//	if (answer.size())
+//	{
+//		for (const int& val : answer)
+//		{
+//			cout << val << "\n";
+//		}
+//	}
+//	else cout << -1;
+//}
+//
+//int main()
+//{
+//	cin.tie(nullptr);
+//	ios::sync_with_stdio(false);
+//
+//	Solve();
+//
+//	return 0;
+//}
+
+#include <iostream>
+#include <queue>
+#include <vector>
+
+using namespace std;
+
+int N, M, K, X, A, B;
+int cur, dist;
+queue<pair<int, int>> q;
+vector<vector<int>> towns;
+vector<bool> visited;
+priority_queue<int, vector<int>, greater<int>> answer;
+
+void Solve()
+{
+	cin >> N >> M >> K >> X;
+
+	N++;
+	towns.assign(N, vector<int>());
+	visited.assign(N, false);
+
+	while (M--)
+	{
+		cin >> A >> B;
+		towns[A].push_back(B);
+	}
+
+	q.push({ X, 0 });
+	visited[X] = true;
+
+	while (!q.empty())
+	{
+		cur = q.front().first;
+		dist = q.front().second;
+
+		q.pop();
+
+		if (dist == K)
+		{
+			answer.push(cur);
+			continue;
+		}
+
+		for (auto v : towns[cur])
+		{
+			if (visited[v]) continue;
+			q.push({ v, dist + 1 });
+			visited[v] = true;
+		}
+	}
+
+	if (answer.empty())
+	{
+		cout << -1;
+		return;
+	}
+
+	while (!answer.empty())
+	{
+		cout << answer.top() << "\n";
+		answer.pop();
+	}
+	return;
+}
+
+int main()
+{
+	cin.tie(nullptr);
+	ios::sync_with_stdio(false);
+
+	Solve();
+
+	return 0;
+}
\ No newline at end of file
diff --git a/InSange/README.md b/InSange/README.md
index 784bfaf..1ab29b3 100644
--- a/InSange/README.md
+++ b/InSange/README.md
@@ -12,6 +12,10 @@
 | 8차시 | 2024.04.09 |  투 포인터  | [두 용액](https://www.acmicpc.net/problem/2470)  | [#8](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/32)]
 | 9차시 | 2024.04.12 |  힙  | [Top K Frequent Words](https://leetcode.com/submissions/detail/1180988760/)  | [#9](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/28)]
 | 10차시 | 2024.04.30 |  스택  | [오아시스 재결합](https://www.acmicpc.net/problem/3015)  | [#10](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/40)]
-| 11차시 | 2024.05.03 |  DFS  | [숫자고르기](https://www.acmicpc.net/problem/2668)  | [#11](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/41)]
+| 11차시 | 2024.05.03 |  DFS  | [숫자고르기](https://www.acmicpc.net/problem/2668)  | [#11](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/41]
 | 12차시 | 2024.05.08 |  DP  | [전깃줄](https://www.acmicpc.net/problem/2565)  | [#12](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/46)]
+| 13차시 | 2024.05.22 |  BFS  | [특정 거리의 도시 찾기](https://www.acmicpc.net/problem/18352)  | [#13](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/53)]
+| 14차시 | 2024.05.27 |  투 포인터  | [포도주 시음](https://www.acmicpc.net/problem/31589)  | [#14](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/56)]
+| 15차시 | 2024.05.27 |  정렬  | [통나무 건너뛰기](https://www.acmicpc.net/problem/11497)  | [#15](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/57)]
+=======
 ---
diff --git "a/InSange/\354\240\225\353\240\254/11497.cpp" "b/InSange/\354\240\225\353\240\254/11497.cpp"
new file mode 100644
index 0000000..f580588
--- /dev/null
+++ "b/InSange/\354\240\225\353\240\254/11497.cpp"
@@ -0,0 +1,61 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+
+using namespace std;
+
+int T, N, num, answer;
+priority_queue < int> pq;
+deque<int> logs;
+
+void Solve()
+{
+	cin >> T;
+
+	while (T--)
+	{
+		answer = 0;
+		cin >> N;
+
+		for (int i = 0; i < N; i++)
+		{
+			cin >> num;
+			pq.push(num);
+		}
+
+		bool isLeft = true;
+
+		while (!pq.empty())
+		{
+			if (isLeft)	
+				logs.push_front(pq.top());
+			else //if(!isLeft)
+				logs.push_back(pq.top());
+
+			pq.pop();
+			isLeft = (isLeft ? false : true);
+		}
+
+		int lsize = logs.size();
+
+		for (int i = 0; i < lsize; i++)
+		{
+			int next = (i + 1) % lsize;
+			answer = max(answer, abs(logs[i] - logs[next]));
+		}
+
+		cout << answer << "\n";;
+		logs.clear();
+	}
+	
+}
+
+int main()
+{
+	ios::sync_with_stdio(false);
+	cin.tie(nullptr);
+
+	Solve();
+
+	return 0;
+}
\ No newline at end of file
diff --git "a/InSange/\355\210\254\355\217\254\354\235\270\355\204\260/31589.cpp" "b/InSange/\355\210\254\355\217\254\354\235\270\355\204\260/31589.cpp"
new file mode 100644
index 0000000..d0ecc02
--- /dev/null
+++ "b/InSange/\355\210\254\355\217\254\354\235\270\355\204\260/31589.cpp"
@@ -0,0 +1,57 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int N, K, l, r, lastDrink;
+vector<int> wine;
+bool isLeft = false;
+long long answer = 0;
+
+void Solve()
+{
+	cin >> N >> K;
+	
+	wine.assign(N, 0);
+
+	for (int i = 0; i < N; i++)
+	{
+		cin >> wine[i];
+	}
+
+	sort(wine.begin(), wine.end());
+
+	l = 0;
+	r = N - 1;
+	answer = 0;
+	lastDrink = 0;
+
+	while (K--)
+	{
+		if (isLeft == true)	// �� ���� ��
+		{
+			lastDrink = wine[l];
+			l++;
+		}
+		else// if(isLeft == false)	// �� �ִ� ��
+		{
+			answer += wine[r] - lastDrink;
+			r--;
+		}
+
+		isLeft = (isLeft + 1) & 1;
+	}
+
+	cout << answer;
+}
+
+int main()
+{
+	ios::sync_with_stdio(false);
+	cin.tie(nullptr);
+
+	Solve();
+
+	return 0;
+}
\ No newline at end of file