diff --git a/InSange/README.md b/InSange/README.md
index 9513d03..6e73fbf 100644
--- a/InSange/README.md
+++ b/InSange/README.md
@@ -28,6 +28,7 @@
 | 24차시 | 2024.08.04 |  BFS  | [트리](https://www.acmicpc.net/problem/1068)  | [#24](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/83)]
 | 25차시 | 2024.08.10 |  BFS  | [Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/)  | [#25](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/87)]
 | 26차시 | 2024.08.11 |  수학  | [Magic Squares In Grid](https://leetcode.com/problems/magic-squares-in-grid/)  | [#26](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/89)]
+| 27차시 | 2024.08.17 |  문자열  | [Number of Senior Citizens](https://leetcode.com/problems/number-of-senior-citizens/)  | [#27](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/91)]
 ---
 
 https://leetcode.com/problems/robot-collisions/
diff --git "a/InSange/\353\254\270\354\236\220\354\227\264/2678_Number of Senior Citizens.cpp" "b/InSange/\353\254\270\354\236\220\354\227\264/2678_Number of Senior Citizens.cpp"
new file mode 100644
index 0000000..656e589
--- /dev/null
+++ "b/InSange/\353\254\270\354\236\220\354\227\264/2678_Number of Senior Citizens.cpp"	
@@ -0,0 +1,24 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    int countSeniors(vector<string>& details) {
+        int seniorCount = 0;
+
+        for (string& passengerInfo : details) {
+            int ageTens = passengerInfo[11] - '0';
+            int ageOnes = passengerInfo[12] - '0';
+
+            int age = ageTens * 10 + ageOnes;
+
+            if (age > 60) {
+                seniorCount++;
+            }
+        }
+
+        return seniorCount;
+    }
+};
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