import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    } main {
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int S = sc.nextInt(); S sc.nextInt() sc.nextInt sc int W = sc.nextInt(); W sc.nextInt() sc.nextInt sc System.out.println(S <= W ? "unsafe" : "safe") System.out.println System.out System System.out S <= W ? "unsafe" : "safe" S <= W S W "unsafe" "safe" String[] args args public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    }
} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        int S = sc.nextInt();
        int W = sc.nextInt();

        System.out.println(S <= W ? "unsafe" : "safe");
    }
}