diff --git a/minsoo/leetcode/preimage_size_of_factorial_zeroes_function.py b/minsoo/leetcode/preimage_size_of_factorial_zeroes_function.py
new file mode 100644
index 0000000..b90c426
--- /dev/null
+++ b/minsoo/leetcode/preimage_size_of_factorial_zeroes_function.py
@@ -0,0 +1,14 @@
+# https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function/
+# ref: https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function/solutions/117821/four-binary-search-solutions-based-on-different-ideas/
+
+
+class Solution:
+    def preimageSizeFZF(self, k: int) -> int:
+        m = 305175781
+        while m > 0:
+            if k == 5 * m:
+                return 0
+            k %= m
+            m = (m - 1) // 5
+
+        return 5