diff --git a/problems/0309.最佳买卖股票时机含冷冻期.md b/problems/0309.最佳买卖股票时机含冷冻期.md
index 18c940d4..2dc1e874 100644
--- a/problems/0309.最佳买卖股票时机含冷冻期.md
+++ b/problems/0309.最佳买卖股票时机含冷冻期.md
@@ -93,7 +93,7 @@ dp[i][3] = dp[i - 1][2];
 综上分析，递推代码如下：
 
 ```CPP
-dp[i][0] = max(dp[i - 1][0], max(dp[i - 1][3], dp[i - 1][1]) - prices[i];
+dp[i][0] = max(dp[i - 1][0], max(dp[i - 1][3], dp[i - 1][1]) - prices[i]);
 dp[i][1] = max(dp[i - 1][1], dp[i - 1][3]);
 dp[i][2] = dp[i - 1][0] + prices[i];
 dp[i][3] = dp[i - 1][2];