diff --git a/bona1122/[week9]Sort/File_sort.js b/bona1122/[week9]Sort/File_sort.js
new file mode 100644
index 0000000..999dcdd
--- /dev/null
+++ b/bona1122/[week9]Sort/File_sort.js
@@ -0,0 +1,33 @@
+// https://school.programmers.co.kr/learn/courses/30/lessons/17686
+
+function solution(files) {
+  const regex = /([^0-9]+)([0-9]+)(.*)/
+  files = files.map((file, idx) => ({
+    name: file,
+    parts: file.match(regex),
+    originalIndex: idx,
+  }))
+
+  files = files.sort((a, b) => {
+    {
+      // HEAD 부분 비교 (대소문자 무시)
+      const headA = a.parts[1].toLowerCase()
+      const headB = b.parts[1].toLowerCase()
+
+      if (headA < headB) return -1
+      if (headA > headB) return 1
+
+      // HEAD가 같으면 NUMBER 부분 비교 (숫자로 비교)
+      const numberA = Number(a.parts[2])
+      const numberB = Number(b.parts[2])
+
+      if (numberA < numberB) return -1
+      if (numberA > numberB) return 1
+
+      // HEAD와 NUMBER가 모두 같으면 원래 순서 유지
+      return a.originalIndex - b.originalIndex
+    }
+  })
+
+  return files.map((file) => file.name)
+}
diff --git a/bona1122/[week9]Sort/H_index.js b/bona1122/[week9]Sort/H_index.js
new file mode 100644
index 0000000..d56ae6a
--- /dev/null
+++ b/bona1122/[week9]Sort/H_index.js
@@ -0,0 +1,16 @@
+// https://school.programmers.co.kr/learn/courses/30/lessons/42747
+// 핵심: 논문을 인용 횟수 기준 내림차순으로 정렬한 후,
+// 논문의 개수(인덱스+1)가 해당 논문의 인용 횟수보다 작거나 같은 최대 지점을 찾는 것
+
+function solution(citations) {
+  citations = citations.sort((a, b) => b - a)
+
+  let i = 0 // 현재까지 확인한 논문의 인덱스
+  // i+1 <= citations[i]가 참이면:
+  // "i+1번 이상 인용된 논문이 i+1편 이상"이라는 의미
+  while (i + 1 <= citations[i]) {
+    i++
+  }
+
+  return i
+}
diff --git a/bona1122/[week9]Sort/Largest_number.js b/bona1122/[week9]Sort/Largest_number.js
new file mode 100644
index 0000000..d30577f
--- /dev/null
+++ b/bona1122/[week9]Sort/Largest_number.js
@@ -0,0 +1,12 @@
+// https://school.programmers.co.kr/learn/courses/30/lessons/42746
+
+function solution(numbers) {
+  const convertString = numbers.map((number) => number.toString())
+  const sorted = convertString.sort((a, b) => {
+    const AB = Number(a + b)
+    const BA = Number(b + a)
+    return BA - AB
+  })
+  const result = sorted.join("")
+  return result[0] === "0" ? "0" : result
+}
diff --git a/bona1122/[week9]Sort/Pick_two_sum.js b/bona1122/[week9]Sort/Pick_two_sum.js
new file mode 100644
index 0000000..e5f84c3
--- /dev/null
+++ b/bona1122/[week9]Sort/Pick_two_sum.js
@@ -0,0 +1,14 @@
+// https://school.programmers.co.kr/learn/courses/30/lessons/68644
+
+const solution = numbers => {
+  const set = new Set();
+  
+  for(let i = 0; i < numbers.length; i++){
+      for(let j = i + 1; j <numbers.length; j++){
+          const num = numbers[i] + numbers[j]
+          set.add(num)
+      }
+  }
+  
+  return [...set].sort((a, b) => a - b)
+}
\ No newline at end of file
diff --git a/bona1122/[week9]Sort/Three_musketeers.js b/bona1122/[week9]Sort/Three_musketeers.js
new file mode 100644
index 0000000..c7130d8
--- /dev/null
+++ b/bona1122/[week9]Sort/Three_musketeers.js
@@ -0,0 +1,24 @@
+// https://school.programmers.co.kr/learn/courses/30/lessons/131705
+
+const solution = (number) => {
+  // 학생은 각자 정수번호가짐
+  // 세명의 번호를 더해서 0이 되면 삼총사, 삼총사 만드는 가짓수 구하기
+  let result = 0
+  const selected = Array(3).fill(0)
+  const dfs = (depth, start) => {
+    if (depth === 3) {
+      let sum = 0
+      for (let i of selected) {
+        sum += number[i]
+      }
+      if (sum === 0) result++
+      return
+    }
+    for (let i = start; i < number.length; i++) {
+      selected[depth] = i
+      dfs(depth + 1, i + 1)
+    }
+  }
+  dfs(0, 0)
+  return result
+}