#include <iostream>
using namespace std;
int main()
{
	int s,w;
	cin>>s>>w;
	if(w>=s)
	{
		cout<<"unsafe";
	}
	else
		cout<<"safe";
}

### Prompt

Please formulate a Cpp solution to the following problem:

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`.

Examples

Input

4 5


Output

unsafe


Input

100 2


Output

safe


Input

10 10


Output

unsafe

### Response

```cpp
#include <iostream>
using namespace std;
int main()
{
	int s,w;
	cin>>s>>w;
	if(w>=s)
	{
		cout<<"unsafe";
	}
	else
		cout<<"safe";
}

```