open System

let [| X; A; B |] = stdin.ReadLine().Split(' ') |> Array.map int
let f x a b = 
    match (x, a, b) with
      | (x, a, b) when -a + b <= 0 -> "delicious"
      | (x, a, b) when -a + b >= (x + 1) -> "dangerous"
      | _ -> "safe"

f X A B |> printfn "%s"
