diff --git "a/\354\243\274\354\244\2218B/jueun/week04/\353\213\244\354\235\214_\355\201\260_\354\210\253\354\236\220.js" "b/\354\243\274\354\244\2218B/jueun/week04/\353\213\244\354\235\214_\355\201\260_\354\210\253\354\236\220.js"
new file mode 100644
index 00000000..848738ef
--- /dev/null
+++ "b/\354\243\274\354\244\2218B/jueun/week04/\353\213\244\354\235\214_\355\201\260_\354\210\253\354\236\220.js"
@@ -0,0 +1,14 @@
+function solution(n) {
+  let binary = n.toString(2);
+  let numOfOnes = binary.split("").filter((el) => el === "1").length;
+
+  while (true) {
+    binary = (++n).toString(2);
+    let newNumOfOnes = binary.split("").filter((el) => el === "1").length;
+    if (numOfOnes === newNumOfOnes) {
+      return n;
+    }
+  }
+
+  return;
+}
diff --git "a/\354\243\274\354\244\2218B/jueun/week04/\354\262\264\354\234\241\353\263\265.js" "b/\354\243\274\354\244\2218B/jueun/week04/\354\262\264\354\234\241\353\263\265.js"
new file mode 100644
index 00000000..ae2efb2b
--- /dev/null
+++ "b/\354\243\274\354\244\2218B/jueun/week04/\354\262\264\354\234\241\353\263\265.js"
@@ -0,0 +1,34 @@
+function solution(n, lost, reserve) {
+  // 바로 앞 or 뒷 번호 학생에게만 빌려줄 수 있다...
+  let students = new Array(n).fill(0);
+
+  for (let i = 0; i < reserve.length; i++) {
+    // students 초기화
+    students[reserve[i] - 1] = "T";
+  }
+  for (let i = 0; i < lost.length; i++) {
+    if (students[lost[i] - 1] === "T") students[lost[i] - 1] = 0;
+    else students[lost[i] - 1] = "L";
+  }
+
+  let possible = 0;
+
+  for (let i = 0; i < n; i++) {
+    if (students[i] !== "L") possible++;
+  }
+
+  for (let i = 0; i < n; i++) {
+    // [ 0, 'L', 'T', 'L', 0 ]
+    if (students[i] === "L") {
+      for (let j = i - 1; j <= i + 1; j++) {
+        if (students[j] === "T") {
+          possible++;
+          students[j] = 0;
+          break;
+        }
+      }
+    }
+  }
+
+  return possible;
+}
diff --git "a/\354\243\274\354\244\2218B/jueun/week04/\354\275\234\353\235\274_\353\254\270\354\240\234.js" "b/\354\243\274\354\244\2218B/jueun/week04/\354\275\234\353\235\274_\353\254\270\354\240\234.js"
new file mode 100644
index 00000000..9b094091
--- /dev/null
+++ "b/\354\243\274\354\244\2218B/jueun/week04/\354\275\234\353\235\274_\353\254\270\354\240\234.js"
@@ -0,0 +1,7 @@
+function solution(a, b, n, answer = 0) {
+  if (n < a) return answer;
+  let quotient = parseInt(n / a);
+  let remainder = n % a;
+  answer += quotient * b;
+  return solution(a, b, remainder + quotient * b, answer);
+}
diff --git "a/\354\243\274\354\244\2218B/jueun/week04/\355\224\274\353\263\264\353\202\230\354\271\230_\354\210\230.js" "b/\354\243\274\354\244\2218B/jueun/week04/\355\224\274\353\263\264\353\202\230\354\271\230_\354\210\230.js"
new file mode 100644
index 00000000..7a718578
--- /dev/null
+++ "b/\354\243\274\354\244\2218B/jueun/week04/\355\224\274\353\263\264\353\202\230\354\271\230_\354\210\230.js"
@@ -0,0 +1,7 @@
+function solution(n) {
+  let fib = [0, 1];
+  for (let i = 2; i <= n; i++) {
+    fib[i] = (fib[i - 1] + fib[i - 2]) % 1234567;
+  }
+  return fib[n];
+}