import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

        if (w >= s) System.out.println("unsafe");
        else System.out.println("safe");
    }
} import java.io.File; File java.io import java.io.FileInputStream; FileInputStream java.io import java.io.FileNotFoundException; FileNotFoundException java.io import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

        if (w >= s) System.out.println("unsafe");
        else System.out.println("safe");
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

        if (w >= s) System.out.println("unsafe");
        else System.out.println("safe");
    } main {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

        if (w >= s) System.out.println("unsafe");
        else System.out.println("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 if (w >= s) System.out.println("unsafe");
        else System.out.println("safe"); w >= s w s System.out.println("unsafe") System.out.println System.out System System.out "unsafe" 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) throws Exception {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

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

        if (w >= s) System.out.println("unsafe");
        else System.out.println("safe");
    }
} Main
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();

        if (w >= s) System.out.println("unsafe");
        else System.out.println("safe");
    }
}
