diff --git a/exercises/Set4b.hs b/exercises/Set4b.hs
index 827235e..3782cf9 100644
--- a/exercises/Set4b.hs
+++ b/exercises/Set4b.hs
@@ -87,7 +87,12 @@ concatHelper x acc = x ++ acc
 largest :: [Int] -> [Int]
 largest xs = foldr largestHelper [] xs
 
-largestHelper = todo
+largestHelper :: Int -> [Int] -> [Int]
+largestHelper x acc 
+  | acc == [] = x : []
+  | x == maximum acc = x : acc 
+  | x > maximum acc = x : [] 
+  | otherwise = acc
 
 
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