Dear Haskell programmers, I'm very confused, because I really don't know how to handle with IO's and other datatypes, such as Int or String. If I want to build a haskell program can I only use IO() method outputs ? How can I "give" a Int result from a different method back to the main? Would this mean that I have to create only IO() outputs? Is this correct? For example: -- A User has to choose something, so I need a IO() datatype main :: IO() main = do [...] let listtournementTime = [8,20,10,15] -- This is wrong: Couldn't match expected type `IO t0' with actual type `Int' -- The results of the method dauer is a Int. Do I have to transform the method to an IO() Output a <- Dauer listtournementTime [...] -- the methods dauer:: [Int] -> Int dauer (x:xs) | laenge(x:xs) == 1 = 0 | mod (laenge (x:xs)) 2 == 0 = (tmp x xs) + dauer xs | mod (laenge (x:xs)) 2 /= 0 = dauer xs | otherwise = 999999 -- failure tmp:: Int -> [Int] -> Int tmp y (x:xs) = x-y laenge :: [a] -> Integer laenge [] = 0 laenge (x:xs) = 1 + laenge xs The last three methods are working correct, if I directly put some data into the methods, like: dauer [10,15] ===Result===> 5 Thank you for any help Best greetings from Namibia