import java.util.*;
import java.util.stream.*;

public class Main {

    public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    }
} import java.util.*; util.* java import java.util.stream.*; stream.* java.util public class Main {

    public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    }
} Main public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    } main {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int sheeps = sc.nextInt(); sheeps sc.nextInt() sc.nextInt sc int wolves = sc.nextInt(); wolves sc.nextInt() sc.nextInt sc System.out.println(sheeps <= wolves ? "unsafe" : "safe") System.out.println System.out System System.out sheeps <= wolves ? "unsafe" : "safe" sheeps <= wolves sheeps wolves "unsafe" "safe" String[] args args public class Main {

    public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    }
} public class Main {

    public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    }
} Main
import java.util.*;
import java.util.stream.*;

public class Main {

    public static void main(String[] args) {
	    // write your code here
        Scanner sc = new Scanner(System.in);
        int sheeps = sc.nextInt();
        int wolves = sc.nextInt();
        System.out.println(sheeps <= wolves ? "unsafe" : "safe");
    }
}
