diff --git a/problems/0509.斐波那契数.md b/problems/0509.斐波那契数.md
index 69306801..08175058 100644
--- a/problems/0509.斐波那契数.md
+++ b/problems/0509.斐波那契数.md
@@ -219,9 +219,6 @@ class Solution:
     def fib(self, n: int) -> int:
        
         # 排除 Corner Case
-        if n == 1:
-            return 1
-
         if n == 0:
             return 0