changed the file structure

Code/Steiner/test/src/App.java

@@ -0,0 +1,12 @@
+public class App {
+    public static void main(String[] args) throws Exception {
+        int smallNumber = 3;
+        int bigNumber = 27;
+        int sum = 0;
+
+        for (int i = smallNumber; i <= bigNumber; i++) {
+            sum = sum + i;
+        }
+        System.out.println(sum);
+    }
+}