import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    }
} Main public static void main(String[] args) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    } main {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int 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 int 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) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    }
} public class Main {
    public static void main(String[] args) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    }
} Main
import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) throws Exception {
 
//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
        Scanner sc = new Scanner(System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        System.out.println(w >= s ? "unsafe":"safe");
    }
}