diff --git a/.idea/.gitignore b/.idea/.gitignore
new file mode 100644
index 00000000..13566b81
--- /dev/null
+++ b/.idea/.gitignore
@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 00000000..2740c6eb
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="corretto-11" project-jdk-type="JavaSDK" />
+</project>
\ No newline at end of file
diff --git a/src/DataTypes.java b/src/DataTypes.java
index 4f807c1f..eeb342c6 100644
--- a/src/DataTypes.java
+++ b/src/DataTypes.java
@@ -3,10 +3,10 @@
 public class DataTypes {
     // TODO TASK 1: fix this code so that it passes the test in DataTypesTest.java
     public static long sum(List<Integer> numbers) {
-
-        int s = 0;
+// this expects a list of integers
+        long s = 0;
         // below is a "foreach" loop which iterates through numbers
-        for (int x : numbers) {
+        for (long x : numbers) {
             s += x;
         }
         return s;