diff --git a/aiden/class4-2/9251.py b/aiden/class4-2/9251.py
new file mode 100644
index 0000000..de60bcd
--- /dev/null
+++ b/aiden/class4-2/9251.py
@@ -0,0 +1,18 @@
+def lcs(s1, s2):
+
+    dp = [[0] * (len(s2) + 1) for _ in range(len(s1) + 1)]
+
+    for i in range(1, len(s1) + 1):
+        for j in range(1, len(s2) + 1):
+            if s1[i-1] == s2[j-1]:
+                dp[i][j] = dp[i-1][j-1] + 1
+
+            else:
+                dp[i][j] = max(dp[i-1][j], dp[i][j-1])
+    
+    return dp[len(s1)][len(s2)]
+        
+s1 = input().strip()
+s2 = input().strip()
+
+print(lcs(s1,s2))
\ No newline at end of file