diff --git a/0503/BOJ/P1620/P1620_lee.java b/0503/BOJ/P1620/P1620_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/BOJ/P1620/P1620_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/0503/BOJ/P1620/P1620_noh.java b/0503/BOJ/P1620/P1620_noh.java
new file mode 100644
index 0000000..186fc3f
--- /dev/null
+++ b/0503/BOJ/P1620/P1620_noh.java
@@ -0,0 +1,29 @@
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        StringBuilder sb = new StringBuilder();
+        int n = sc.nextInt();
+        int m = sc.nextInt();
+
+        String[] idxToName = new String[n + 1];
+        Map<String, Integer> nameToIdx = new HashMap<String, Integer>();
+
+        for (int i = 1; i <= n; ++i) {
+            String name = sc.next();
+            idxToName[i] = name;
+            nameToIdx.put(name, i);
+        }
+        for (int i = 0; i < m; ++i) {
+            String input = sc.next();
+            if ('0' <= input.charAt(0) && input.charAt(0) <= '9')
+                sb.append(idxToName[Integer.parseInt(input)] + "\n");
+            else
+                sb.append(nameToIdx.get(input) + "\n");
+        }
+        System.out.print(sb);
+    }
+}
\ No newline at end of file
diff --git a/0503/BOJ/P1676/P1676_lee.java b/0503/BOJ/P1676/P1676_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/BOJ/P1676/P1676_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/0503/BOJ/P1676/P1676_noh.java b/0503/BOJ/P1676/P1676_noh.java
new file mode 100644
index 0000000..567c687
--- /dev/null
+++ b/0503/BOJ/P1676/P1676_noh.java
@@ -0,0 +1,22 @@
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        int two = 0;
+        int five = 0;
+        for (int i = 2; i <= n; ++i) {
+            int temp = i;
+            while (temp % 2 == 0) {
+                temp /= 2;
+                ++two;
+            }
+            while (temp % 5 == 0) {
+                temp /= 5;
+                ++five;
+            }
+        }
+        System.out.println(Math.min(two, five));
+    }
+}
\ No newline at end of file
diff --git a/0503/BOJ/P1697/P1697_lee.java b/0503/BOJ/P1697/P1697_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/BOJ/P1697/P1697_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/0503/BOJ/P1697/P1697_noh.java b/0503/BOJ/P1697/P1697_noh.java
new file mode 100644
index 0000000..2472077
--- /dev/null
+++ b/0503/BOJ/P1697/P1697_noh.java
@@ -0,0 +1,39 @@
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        int k = sc.nextInt();
+
+        Queue<Integer> q = new LinkedList<Integer>();
+        q.add(n);
+        boolean[] visited = new boolean[200001];
+
+        int time = 0;
+        while (!q.isEmpty()) {
+            int size = q.size();
+            for (int i = 0; i < size; ++i) {
+                int cur = q.poll();
+                if (visited[cur])
+                    continue;
+                visited[cur] = true;
+
+                if (cur == k) {
+                    System.out.println(time);
+                    return;
+                }
+
+                if (cur - 1 >= 0)
+                    q.add(cur - 1);
+                if (cur + 1 <= 100000)
+                    q.add(cur + 1);
+                if (cur * 2 <= 200000)
+                    q.add(cur * 2);
+            }
+            ++time;
+        }
+    }
+}
\ No newline at end of file
diff --git a/0503/Programmers/Lv1/Lv1_lee.java b/0503/Programmers/Lv1/Lv1_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/Programmers/Lv1/Lv1_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/0503/Programmers/Lv2/Lv2_lee.java b/0503/Programmers/Lv2/Lv2_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/Programmers/Lv2/Lv2_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/0503/Programmers/Lv3/Lv3_lee.java b/0503/Programmers/Lv3/Lv3_lee.java
deleted file mode 100644
index 8b13789..0000000
--- a/0503/Programmers/Lv3/Lv3_lee.java
+++ /dev/null
@@ -1 +0,0 @@
-