diff --git a/09/MirageMaintenance.Tests/OasisReportTests.cs b/09/MirageMaintenance.Tests/OasisReportTests.cs
index d3ffdb3..c69fc91 100644
--- a/09/MirageMaintenance.Tests/OasisReportTests.cs
+++ b/09/MirageMaintenance.Tests/OasisReportTests.cs
@@ -6,7 +6,10 @@ public class UnitTest1
   [MemberData(nameof(TestData.OasisReportParseTestData), MemberType = typeof(TestData))]
   public void Parse_GivenAReportInput_ItShouldReturnExpectedOasisReportInstance(string[] input, OasisReport expected)
   {
-    OasisReport.Parse(input).Should().BeEquivalentTo(expected);
+    OasisReport
+      .Parse(input)
+      .Should()
+      .BeEquivalentTo(expected);
   }
 
   [Fact]
@@ -19,11 +22,37 @@ public class UnitTest1
       "10 13 16 21 30 45",
     };
 
-    OasisReport.Parse(input).CalculateSumOfNextValues().Should().Be(114);
+    OasisReport
+      .Parse(input)
+      .CalculateSumOfNextValues()
+      .Should()
+      .Be(114);
+  }
+
+  [Fact]
+  public void CalculateSumOfNextValues_WhenGivenInput_ItShouldReturnTheSumOfAllNextValues()
+  {
+    OasisReport
+      .Parse(TestData.Input)
+      .CalculateSumOfNextValues()
+      .Should()
+      .Be(2175229206);
+  }
+
+  [Fact]
+  public void CalculateSumOfNextValues_WhenGivenInputAndBackwardsIsTrue_ItShouldReturnTheSumOfAllNextValues()
+  {
+    OasisReport
+      .Parse(TestData.Input)
+      .CalculateSumOfNextValues(true)
+      .Should()
+      .Be(942);
   }
 
   public static class TestData
   {
+    public static readonly string[] Input = File.ReadAllLines("INPUT.txt");
+
     public static IEnumerable<object[]> OasisReportParseTestData =>
       new List<object[]>
       {
diff --git a/09/MirageMaintenance.Tests/ValueHistoryTests.cs b/09/MirageMaintenance.Tests/ValueHistoryTests.cs
index 1804854..828ae2e 100644
--- a/09/MirageMaintenance.Tests/ValueHistoryTests.cs
+++ b/09/MirageMaintenance.Tests/ValueHistoryTests.cs
@@ -6,28 +6,40 @@ public class ValueHistoryTests
   [MemberData(nameof(TestData.CalculateDifferencesTestData), MemberType = typeof(TestData))]
   public void CalculateDifferences_GivenAListOfValues_ItShouldReturnAListOfDifferences(List<long> values, List<long> expected)
   {
-    new ValueHistory([]).CalculateDifferences(values).Should().BeEquivalentTo(expected);
+    new ValueHistory([])
+      .CalculateDifferences(values)
+      .Should()
+      .BeEquivalentTo(expected);
   }
 
   [Theory]
   [MemberData(nameof(TestData.CalculateHistoryTestData), MemberType = typeof(TestData))]
   public void CalculateHistory_GivenAListOfValues_ItShouldReturnAListOfHistoricalValues(List<long> values, List<List<long>> expected)
   {
-    new ValueHistory(values).CalculateHistory().Should().BeEquivalentTo(expected);
+    new ValueHistory(values)
+      .CalculateHistory()
+      .Should()
+      .BeEquivalentTo(expected);
   }
 
   [Theory]
   [MemberData(nameof(TestData.CalculateNextValueTestData), MemberType = typeof(TestData))]
   public void CalculateNextValue_GivenAListOfValues_ItShouldReturnTheNextValue(List<long> values, long expected)
   {
-    new ValueHistory(values).CalculateNextValue().Should().Be(expected);
+    new ValueHistory(values)
+      .CalculateNextValue()
+      .Should()
+      .Be(expected);
   }
 
   [Theory]
   [MemberData(nameof(TestData.CalculateNextValueTestDataBackwards), MemberType = typeof(TestData))]
   public void CalculateNextValue_GivenAListOfValuesAndBackwardsIsTrue_ItShouldReturnTheNextValue(List<long> values, long expected)
   {
-    new ValueHistory(values).CalculateNextValue(true).Should().Be(expected);
+    new ValueHistory(values)
+      .CalculateNextValue(true)
+      .Should()
+      .Be(expected);
   }
 
   public static class TestData