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

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    }
} import java.util.*; util.* java import java.util.stream.*; stream.* java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    } main {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int s = sc.nextInt() s sc.nextInt() sc.nextInt sc w = sc.nextInt(); w sc.nextInt() sc.nextInt sc System.out.println(w >= s ? "unsafe" : "safe") System.out.println System.out System System.out w >= s ? "unsafe" : "safe" w >= s w s "unsafe" "safe" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt(), w = sc.nextInt();
        System.out.println(w >= s ? "unsafe" : "safe");
    }
} Main
import java.util.*;
import java.util.stream.*;

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