diff --git a/alstjr7437/README.md b/alstjr7437/README.md
index 035553e..cd988a3 100644
--- a/alstjr7437/README.md
+++ b/alstjr7437/README.md
@@ -6,4 +6,5 @@
 | 2차시 | 2025.04.08 |  Heap  | [최대힙](https://www.acmicpc.net/problem/11279)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/7|
 | 3차시 | 2025.04.30 |  투포인터  | [먹을 것인가 먹힐 것인가](https://www.acmicpc.net/problem/7795)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/17|
 | 4차시 | 2025.05.13 |  구현  | [후보 추천하기](https://www.acmicpc.net/problem/1713)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/24|
+| 5차시 | 2025.05.22 |  이분탐색  | [퍼즐게임 챌린지](https://school.programmers.co.kr/learn/courses/30/lessons/340212)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/27|
 ---
diff --git "a/alstjr7437/\354\235\264\353\266\204\355\203\220\354\203\211/\355\215\274\354\246\220\352\262\214\354\236\204\354\262\264\354\235\270\354\247\200_\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244.swift" "b/alstjr7437/\354\235\264\353\266\204\355\203\220\354\203\211/\355\215\274\354\246\220\352\262\214\354\236\204\354\262\264\354\235\270\354\247\200_\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244.swift"
new file mode 100644
index 0000000..224ddfb
--- /dev/null
+++ "b/alstjr7437/\354\235\264\353\266\204\355\203\220\354\203\211/\355\215\274\354\246\220\352\262\214\354\236\204\354\262\264\354\235\270\354\247\200_\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244.swift"
@@ -0,0 +1,39 @@
+import Foundation
+
+func puzzle(diffs: [Int], times: [Int], level: Int) -> Int{
+    var result = 0
+    for i in 0..<diffs.count {
+        if diffs[i] <= level {
+            result += times[i]
+        } else {
+            let discorrectCount = diffs[i] - level
+            let discorrectUseTime = times[i - 1] + times[i]
+            let totalUseTime = discorrectUseTime * discorrectCount + times[i]
+            result += totalUseTime
+        }
+    }
+    
+    return result
+}
+
+
+func solution(_ diffs:[Int], _ times:[Int], _ limit:Int64) -> Int {
+    var start = 1
+    var end = diffs.max() ?? 100000
+    var mid = 0
+    var answer = 0
+    
+    while start <= end {
+        mid =  (start + end) / 2
+        let result = puzzle(diffs: diffs, times: times, level: mid)
+        
+        if result <= limit {
+            answer = mid  
+            end = mid - 1     
+        } else {
+            start = mid + 1     
+        }
+    }
+    
+    return answer
+}
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