diff --git a/medium/successful_pairs_of_spells_and_potions.py b/medium/successful_pairs_of_spells_and_potions.py
new file mode 100644
index 0000000..cbbe368
--- /dev/null
+++ b/medium/successful_pairs_of_spells_and_potions.py
@@ -0,0 +1,20 @@
+# https://leetcode.com/problems/successful-pairs-of-spells-and-potions
+
+from typing import List
+
+class Solution:
+    def successfulPairs(self, spells: List[int], potions: List[int], success: int) -> List[int]:
+        potions.sort()
+        for i in range(len(spells)):
+            spell = spells[i]
+            left = 0
+            right = len(potions) - 1
+            while left <= right:
+                mid = (left + right) // 2
+                if spell * potions[mid] >= success:
+                    right = mid - 1
+                else:
+                    left = mid + 1
+            spells[i] = len(potions) - left
+        return spells
+