Sheep and Wolves

Source: AtCoder

Problem Statement

There are $S$ sheep and $W$ wolves. The sheep are unsafe when the number of wolves is at least the number of sheep.

Input

One line contains $S$ and $W$.

Output

Print unsafe if $W \ge S$; otherwise print safe.

Subtasks

• Subtask 1 (100%): $1 \le S,W \le 100$

Examples

Example 1

Input

4 5

Output

unsafe

Explanation

For the sample values 4, 5, evaluating the conditions in the statement gives unsafe. Therefore the program prints the shown output.

Example 2

Input

100 2

Output

safe

Explanation

For the sample values 100, 2, evaluating the conditions in the statement gives safe. Therefore the program prints the shown output.

Example 3

Input

10 10

Output

unsafe

Explanation

For the sample values 10, 10, evaluating the conditions in the statement gives unsafe. Therefore the program prints the shown output.