import java.util.*;

public class Main {
    public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} import java.util.*; util.* java public class Main {
    public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } main {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int sheep = Integer.parseInt(sc.next()); sheep Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int wolves = Integer.parseInt(sc.next()); wolves Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        } sheep <= wolves sheep wolves {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" {
            System.out.println("safe");
        } System.out.println("safe") System.out.println System.out System System.out "safe" String[] args args public class Main {
    public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} public class Main {
    public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main
import java.util.*;

public class Main {
    public  static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int sheep = Integer.parseInt(sc.next());
        int wolves = Integer.parseInt(sc.next());

        if(sheep <= wolves) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
}