it's works

.gitignore

@@ -1,3 +1,4 @@
 .idea/*
+*.skill
 *.iml
 target/*

pom.xml

@@ -9,7 +9,7 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <jdk.version>11</jdk.version>
+        <jdk.version>17</jdk.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <maven.checkstyle.plugin.version>3.1.1</maven.checkstyle.plugin.version>

src/main/java/core/basesyntax/MyTask.java

@@ -3,6 +3,7 @@
 import java.util.concurrent.RecursiveTask;
 
 public class MyTask extends RecursiveTask<Long> {
+    public static final int MAX = 10;
     private int startPoint;
     private int finishPoint;
 
@@ -13,7 +14,18 @@ public MyTask(int startPoint, int finishPoint) {
 
     @Override
     protected Long compute() {
-        // write your code here
-        return null;
+        int length = finishPoint - startPoint; // Это и есть ваш workLoad
+        if (length <= MAX) {
+            long sum = 0;
+            for (int i = startPoint; i < finishPoint; i++) {
+                sum += i;
+            }
+            return sum;
+        }
+        int middle = startPoint + (finishPoint - startPoint) / 2;
+        MyTask leftTask = new MyTask(startPoint, middle);
+        MyTask rightTask = new MyTask(middle, finishPoint);
+        leftTask.fork(); // Запускаем одну задачу асинхронно
+        return rightTask.compute() + leftTask.join();
     }
 }