diff --git a/luogu/P2866.py b/luogu/P2866.py
index 0c501f4..0f81b6b 100644
--- a/luogu/P2866.py
+++ b/luogu/P2866.py
@@ -1,6 +1,11 @@
 N = int(input())
 length = [int(input()) for i in range(N)]
 
+# N <= 8 * 10**4, length <= 10**9
+
+# method 1, has some time exceeded
+
+"""
 sum = 0
 
 for i in range(N):
@@ -9,6 +14,17 @@ for i in range(N):
 			sum += 1
 		elif length[i] <= length[j]:
 			break
+"""
 
+# method 2
+
+sum = 0
+i = 0
+while i < N:
+    for j in range(i + 1, N):
+        if length[i] > length[j]:
+            sum += 1
+        elif length[i] <= length[j]:
+            # maybe something here?
+            break
 print(sum)
-