import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    }
} import java.util.*; util.* java public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    }
} Main public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    } main {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    } Scanner  yomi = new Scanner(System.in); yomi new Scanner(System.in) int n = yomi.nextInt(); n yomi.nextInt() yomi.nextInt yomi int m = yomi.nextInt(); m yomi.nextInt() yomi.nextInt yomi System.out.println(n-m>0 ? "safe" : "unsafe") System.out.println System.out System System.out n-m>0 ? "safe" : "unsafe" n-m>0 n-m n m 0 "safe" "unsafe" String[] args args public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    }
} public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    }
} Main
import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner  yomi = new Scanner(System.in);
        int n = yomi.nextInt();
        int m = yomi.nextInt();
        System.out.println(n-m>0 ? "safe" : "unsafe");

    }
}