diff --git a/Program.cs b/Program.cs
index 65f1064..c48927e 100644
--- a/Program.cs
+++ b/Program.cs
@@ -57,6 +57,7 @@ namespace Euler {
   		primes.Add(2);
   		for (int i = 3; i <= num; i += 2) {
   			if (IsPrime(i, primes)) {
+          WriteLine(i);
   				primes.Add(i);
   			}
   		}
@@ -212,8 +213,19 @@ namespace Euler {
       return 0;
     }
 
+    [Fact]
+    static long Problem10() {
+      List<long> primes = PrimesUpThrough(2_000_000);
+      long sum = 0;
+      foreach (long prime in primes) {
+        sum += prime;
+      }
+      Assert.Equal(142913828922, sum);
+      return sum;
+    }
+
     static void Main(string[] args) {
-      WriteLine(Problem9());
+      WriteLine(Problem10());
     }
   }
 }