diff --git "a/live8/test84/\353\254\270\354\240\2341/\355\231\251\354\236\245\355\230\204.js" "b/live8/test84/\353\254\270\354\240\2341/\355\231\251\354\236\245\355\230\204.js"
new file mode 100644
index 00000000..2d7d05cd
--- /dev/null
+++ "b/live8/test84/\353\254\270\354\240\2341/\355\231\251\354\236\245\355\230\204.js"
@@ -0,0 +1,41 @@
+const input = require('fs')
+  .readFileSync(process.platform === 'linux' ? '/dev/stdin' : './input.txt')
+  .toString()
+  .trim()
+  .split('\n')
+  .map((el) => el.split(' ').map(Number));
+
+function solution(input) {
+  const T = input[0];
+  let idx = 1;
+  let result = [];
+  for (let i = 0; i < T; i++) {
+    const [N, M] = input[idx];
+    const A = input[idx + 1];
+    const B = input[idx + 2];
+    A.sort((a, b) => a - b);
+    B.sort((a, b) => a - b);
+    let count = 0;
+    const bMaxNum = Math.max(...B);
+
+    for (let j = 0; j < N; j++) {
+      if (A[j] > bMaxNum) {
+        count += M;
+        continue;
+      }
+      for (let k = 0; k < M; k++) {
+        if (A[j] > B[k]) count++;
+        else break;
+      }
+    }
+    result.push(count);
+
+    idx += 3;
+  }
+  return result.join('\n');
+}
+
+console.log(solution(input));
+
+// 노가다로 풀었더니 이진탐색이랑 4배 차이 ㄷㄷ
+// 배열에서 원하값 찾을 때 이진탐색 생각하기
diff --git "a/live8/test84/\353\254\270\354\240\2342/\355\231\251\354\236\245\355\230\204.js" "b/live8/test84/\353\254\270\354\240\2342/\355\231\251\354\236\245\355\230\204.js"
new file mode 100644
index 00000000..38854a1f
--- /dev/null
+++ "b/live8/test84/\353\254\270\354\240\2342/\355\231\251\354\236\245\355\230\204.js"
@@ -0,0 +1,31 @@
+const input = require('fs')
+  .readFileSync(process.platform === 'linux' ? '/dev/stdin' : './input.txt')
+  .toString()
+  .trim()
+  .split('\n')
+  .map((el) => el.split(' ').map(Number));
+
+function solution(input) {
+  const [K, N] = input[0];
+  const lanList = input.slice(1);
+
+  let low = 1;
+  let high = Math.max(...lanList);
+  let answer = 0;
+
+  while (low <= high) {
+    let mid = Math.floor((low + high) / 2);
+    let count = lanList.reduce((acc, cur) => acc + Math.floor(cur / mid), 0);
+
+    if (count >= N) {
+      answer = mid;
+      low = mid + 1;
+    } else {
+      high = mid - 1;
+    }
+  }
+
+  return answer;
+}
+
+console.log(solution(input));
diff --git "a/live8/test84/\353\254\270\354\240\2343/\355\231\251\354\236\245\355\230\204.js" "b/live8/test84/\353\254\270\354\240\2343/\355\231\251\354\236\245\355\230\204.js"
new file mode 100644
index 00000000..009132c5
--- /dev/null
+++ "b/live8/test84/\353\254\270\354\240\2343/\355\231\251\354\236\245\355\230\204.js"
@@ -0,0 +1,15 @@
+function solution(skill, skill_trees) {
+  let count = 0;
+
+  skill_trees.forEach((tree) => {
+    let filtered = tree
+      .split('')
+      .filter((s) => skill.includes(s))
+      .join('');
+    if (skill.startsWith(filtered)) count++;
+  });
+
+  return count;
+}
+
+console.log(solution('CBD', ['BACDE', 'CBADF', 'AECB', 'BDA']));