Problem:
Score : 100 points

Problem Statement

There are S sheep and W wolves.

If the number of wolves is greater than or equal to that of sheep, the wolves will attack the sheep.

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Constraints

1 \leq S \leq 100

1 \leq W \leq 100

Input

Input is given from Standard Input in the following format:

S W

Output

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Sample Input 1

4 5

Sample Output 1

unsafe

There are four sheep and five wolves. The number of wolves is not less than that of sheep, so they will attack them.

Sample Input 2

100 2

Sample Output 2

safe

Many a sheep drive away two wolves.

Sample Input 3

10 10

Sample Output 3

unsafe

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Time Limit Exceeded)

const Main = (input) => {
  const tmp = input.split(' ')
  const takahashi = { hp: tmp[0], atk: tmp[1] }
  const aoki = { hp: tmp[2], atk: tmp[3] }

  let i = 0
  let result = ''
  let winner = ''

  const player = { takahashi: takahashi, aoki: aoki }
  const players = ['takahashi', 'aoki']
  while (true) {
    const attacker = players[i % 2]
    const defender = players[(i + 1) % 2]
    player[defender].hp = player[defender].hp - player[attacker].atk
    if (player[defender].hp <= 0) {
      winner = attacker
      break
    }
    i += 1
  }

  if (winner === 'takahashi') {
    result = 'yes'
  } else {
    result = 'no'
  }

  console.log(result)
  return result
}

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