Add basic Project Euler solutions

project-euler-haskell/problem2.hs

@@ -0,0 +1,10 @@
+fn :: Integer -> Integer -> Integer -> Integer
+fn m n max | m == 0 = fn n 1 max
+           | sum >= max = 0
+           | even sum = sum + fn n sum max
+           | odd sum = fn n sum max
+           | otherwise = 0
+    where sum = m+n
+main = do 
+   putStrLn "The sum of the even Fibonacci numbers below 4000 is:"  
+   print (fn 0 0 4000)