diff --git a/pu2rile/README.md b/pu2rile/README.md
index 58e9799..f04c429 100644
--- a/pu2rile/README.md
+++ b/pu2rile/README.md
@@ -5,4 +5,4 @@
 | 1차시 | 2024.03.24 |  DP  | [평범한 배낭](https://www.acmicpc.net/problem/12865)  | [#3](https://github.com/AlgoLeadMe/AlgoLeadMe-10/pull/3#issue-2205834078)|
 | 2차시 | 2024.03.29 |  구현  | [OX퀴즈](https://www.acmicpc.net/problem/8958)  | [#6](https://github.com/AlgoLeadMe/AlgoLeadMe-10/pull/6#issue-2214931034)|
 | 3차시 | 2024.04.02 |  문자열  | [크로아티아 알파벳](https://www.acmicpc.net/problem/8958)  | [#10](https://github.com/AlgoLeadMe/AlgoLeadMe-10/pull/10#issue-2220631332)
-| 4차시 | 2024.04.08 |  스택  | [제로](https://www.acmicpc.net/problem/10773)  | [#]()
+| 4차시 | 2024.04.08 |  스택  | [제로](https://www.acmicpc.net/problem/10773)  | [#15](https://github.com/AlgoLeadMe/AlgoLeadMe-10/pull/15#issue-2229909173)