une' a b (x:xs) c= if(c==a) then (b:xs)
 else x:une' a b (xs) (c+1)
une' a b (x:xs) c= if(c==a) then (b:xs)
 else x:une' a b (xs) (c+1)
une' a b (x:xs) c= if(c==a) then (b:xs)
 else x:une' a b (xs) (c+1)