'use strict'

const main = input => {
	const args = input.split('\n').map(arg => arg.split(' '))
	const X = parseInt(args[0][0], 10)
	const A = parseInt(args[0][1], 10)
	const B = parseInt(args[0][2], 10)
	if (A - B >= -1) console.log('delicious')
	else if (Math.abs(A - B) < X + 1) console.log('safe')
	else console.log('dangerous')
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))
