import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  }
} Main public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  } main {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) int S = scan.nextInt(); S scan.nextInt() scan.nextInt scan int W = scan.nextInt(); W scan.nextInt() scan.nextInt scan scan.close() scan.close scan 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 scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  }
} public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    int S = scan.nextInt();
    int W = scan.nextInt();
    scan.close();

    System.out.println(W>=S ? "unsafe" : "safe");
  }
}