'use strict'

function main(input) {
  input = input.split(' ').map(v => ~~v)

  const x = input[0]
  const a = input[1]
  const b = input[2]
  const c = a - b

  let ans = ''

  if (c >= 0) {
    ans = 'delicious'
  } else if (x + a >= b) {
    ans = 'safe'
  } else {
    ans = 'dangerous'
  }
  console.log(ans)
}
main(require("fs").readFileSync("/dev/stdin", "utf8"));