Contest Duration: - (local time) (100 minutes) Back to Home
A - Sheep and Wolves /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 1 \leq S \leq 100
• 1 \leq W \leq 100

### 入力

S W


### 入力例 1

4 5


### 出力例 1

unsafe


### 入力例 2

100 2


### 出力例 2

safe


### 入力例 3

10 10


### 出力例 3

unsafe


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