diff --git "a/leetcode3/\355\231\251\354\235\200\354\247\200/3827. Count Monobit Integers.js" "b/leetcode3/\355\231\251\354\235\200\354\247\200/3827. Count Monobit Integers.js"
new file mode 100644
index 00000000..4832364d
--- /dev/null
+++ "b/leetcode3/\355\231\251\354\235\200\354\247\200/3827. Count Monobit Integers.js"	
@@ -0,0 +1,13 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var countMonobit = function(n) {
+    // 0은 꼭 포함, 나머지는 전부 1로만 이루어짐
+    let count=1;
+    const binary=n.toString(2);
+    count+=(binary.length-1);
+    if(!binary.includes("0")) count+=1;
+
+    return count;
+};
\ No newline at end of file