diff --git a/.gitignore b/.gitignore
index dd5c568..73dcb74 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 .DS_Store
+.idea/
 /.vscode
diff --git a/g0rnn/README.md b/g0rnn/README.md
index c427fa7..f8dcc1e 100644
--- a/g0rnn/README.md
+++ b/g0rnn/README.md
@@ -9,6 +9,7 @@
 | 5차시 | 2024.11.01 |  BFS/DFS   |                [연구소](https://www.acmicpc.net/problem/14502)                | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/17 |
 | 6차시 | 2024.11.06 |    구현    |                [통계학](https://www.acmicpc.net/problem/2108)                 | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/23 |
 | 7차시 | 2024.11.25 |    구현    |            [팰린드롬 만들기](https://www.acmicpc.net/problem/1213)            | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/31 |
-| 8차시 | 2024.11.29 |    문자열    |            [잠수함식별](https://www.acmicpc.net/problem/2671)            | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/35 |
+| 8차시 | 2024.11.29 | 문자열 | [잠수함식별](https://www.acmicpc.net/problem/2671) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/35 |
+| 9차시 | 2024.12.04 | 그리디 | [A->B](https://www.acmicpc.net/problem/16953) | https://github.com/AlgoLeadMe/AlgoLeadMe-12/pull/39 |
 
 ---
diff --git a/g0rnn/greedy/9-g0rnn.cpp b/g0rnn/greedy/9-g0rnn.cpp
new file mode 100644
index 0000000..6f70e28
--- /dev/null
+++ b/g0rnn/greedy/9-g0rnn.cpp
@@ -0,0 +1,27 @@
+//
+// Created by 김균호 on 2024. 12. 4..
+//
+#include <iostream>
+using namespace std;
+
+int a, b, answer = 1;
+
+int main() {
+	cin >> a >> b;
+
+	while (a < b) {
+		if (b % 2 == 0) {
+			b = b / 2;
+		} else if (b % 10 == 1) {
+			b /= 10;
+		} else {
+			break;
+		}
+		answer++;
+	}
+
+	if(a == b) cout << answer;
+	else cout << -1;
+
+	return 0;
+}
\ No newline at end of file