diff --git "a/leetcode3/\354\265\234\354\233\220\354\244\200/3803. Count Residue Prefixes.py" "b/leetcode3/\354\265\234\354\233\220\354\244\200/3803. Count Residue Prefixes.py"
new file mode 100644
index 00000000..d8f3d91c
--- /dev/null
+++ "b/leetcode3/\354\265\234\354\233\220\354\244\200/3803. Count Residue Prefixes.py"	
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+#
+
+'''
+1. 아이디어 :
+dictionary를 사용해서 distinct를 유지한다.
+
+2. 시간복잡도 :
+    O(n)
+
+3. 자료구조/알고리즘 :
+-
+
+'''
+from collections import defaultdict
+class Solution:
+    def residuePrefixes(self, s: str) -> int:
+        counter = defaultdict(int)
+        distinct = 0
+        ans = 0
+
+        for i in range(len(s)):
+            char = s[i]
+            if counter[char] == 0:
+                distinct +=1
+            counter[char] +=1
+            if (i+1) % 3 == distinct:
+                ans+=1
+        return ans