diff --git a/pu2rile/README.md b/pu2rile/README.md
index 1a26feb..58e9799 100644
--- a/pu2rile/README.md
+++ b/pu2rile/README.md
@@ -5,3 +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)  | [#]()
diff --git "a/pu2rile/\354\212\244\355\203\235/\354\240\234\353\241\234.py" "b/pu2rile/\354\212\244\355\203\235/\354\240\234\353\241\234.py"
new file mode 100644
index 0000000..f02b9be
--- /dev/null
+++ "b/pu2rile/\354\212\244\355\203\235/\354\240\234\353\241\234.py"
@@ -0,0 +1,9 @@
+k = int(input())
+stack = []
+for _ in range(k):
+  n = int(input())
+  if n == 0:
+    stack.pop()
+  else:
+    stack.append(n)
+print(sum(stack))
\ No newline at end of file