diff --git a/luogu/P2866.py b/luogu/P2866.py
new file mode 100644
index 0000000..0c501f4
--- /dev/null
+++ b/luogu/P2866.py
@@ -0,0 +1,14 @@
+N = int(input())
+length = [int(input()) for i in range(N)]
+
+sum = 0
+
+for i in range(N):
+	for j in range(i+1,N):
+		if length[i] > length[j]:
+			sum += 1
+		elif length[i] <= length[j]:
+			break
+
+print(sum)
+