diff --git a/_hyunseo/9527.py b/_hyunseo/9527.py
new file mode 100644
index 00000000..b1a28607
--- /dev/null
+++ b/_hyunseo/9527.py
@@ -0,0 +1,22 @@
+import sys,math
+
+sys.setrecursionlimit( 10 ** 8)
+input = map(int, input().split())
+
+def sum_f ( x) :
+  if x <= 0 :
+    return 0
+
+  seung = int(math.log2(x))
+  floor_2pow = 2 ** seung
+
+  # 2, 4, 8, 16, 32 ...
+  if floor_2pow == x :
+    return seung*x // 2 + 1 
+
+  diff = x - floor_2pow
+  # 10 = 8 + 2
+  return sum_f(floor_2pow) + diff + sum_f(diff)
+
+a, b = map(int, input().split())
+print(sum_f(b) - sum_f(a - 1))