diff --git a/src/main/java/com/fishercoder/solutions/_636.java b/src/main/java/com/fishercoder/solutions/_636.java
index bc19f179b6..34b36a5a11 100644
--- a/src/main/java/com/fishercoder/solutions/_636.java
+++ b/src/main/java/com/fishercoder/solutions/_636.java
@@ -41,31 +41,35 @@
  1 <= n <= 100
  */
 public class _636 {
-    /**Based on the example, it's difficult to see how function 2 executes 4 units of time, actually
-     * we can add 1 to all end times to make it easier to understand and AC'ed.*/
-    public int[] exclusiveTime(int n, List<String> logs) {
-        /**Stack is the way to go:
-         * we keep pushing the logId onto the stack whenever we just encounter this logId's start timestamp,
-         * we'll pop this logId only when we encounter this logId's end timestamp.
-         * Meanwhile, we keep a counter called prevTime,
-         * whenever the stack is not empty, we'll always deduct prevTime from the last logId on the stack.*/
-        Deque<Integer> stack = new LinkedList<>();
-        int[] result = new int[n];
-        int prevTime = 0;
-        for (String log : logs) {
-            String[] parts = log.split(":");
-            if (!stack.isEmpty()) {
-                result[stack.peek()] += Integer.parseInt(parts[2]) - prevTime;
-            }
-            prevTime = Integer.parseInt(parts[2]);
-            if (parts[1].equals("start")) {
-                stack.addFirst(Integer.parseInt(parts[0]));//i.e. stack.push()
-            } else {
-                prevTime++;
-                //remember to have result pluse 1 to match the problem AC criteria
-                result[stack.pollFirst()]++;//i.e. stack.pop()
+    public static class Solution1 {
+        /**
+         * Based on the example, it's difficult to see how function 2 executes 4 units of time, actually
+         * we can add 1 to all end times to make it easier to understand and AC'ed.
+         */
+        public int[] exclusiveTime(int n, List<String> logs) {
+            /**Stack is the way to go:
+             * we keep pushing the logId onto the stack whenever we just encounter this logId's start timestamp,
+             * we'll pop this logId only when we encounter this logId's end timestamp.
+             * Meanwhile, we keep a counter called prevTime,
+             * whenever the stack is not empty, we'll always deduct prevTime from the last logId on the stack.*/
+            Deque<Integer> stack = new LinkedList<>();
+            int[] result = new int[n];
+            int prevTime = 0;
+            for (String log : logs) {
+                String[] parts = log.split(":");
+                if (!stack.isEmpty()) {
+                    result[stack.peek()] += Integer.parseInt(parts[2]) - prevTime;
+                }
+                prevTime = Integer.parseInt(parts[2]);
+                if (parts[1].equals("start")) {
+                    stack.addFirst(Integer.parseInt(parts[0]));//i.e. stack.push()
+                } else {
+                    prevTime++;
+                    //remember to have result pluse 1 to match the problem AC criteria
+                    result[stack.pollFirst()]++;//i.e. stack.pop()
+                }
             }
+            return result;
         }
-        return result;
     }
 }