import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  }
} Main public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  } main {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  } Scanner s = new Scanner(System.in); s new Scanner(System.in) final int SHEEP_NUM = s.nextInt(); SHEEP_NUM s.nextInt() s.nextInt s final int WOLF_NUM = s.nextInt(); WOLF_NUM s.nextInt() s.nextInt s if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    } SHEEP_NUM <= WOLF_NUM SHEEP_NUM WOLF_NUM {
        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 s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  }
} public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

    if (SHEEP_NUM <= WOLF_NUM) {
        System.out.println("unsafe");
    } else {
        System.out.println("safe");
    }
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner s = new Scanner(System.in);
    final int SHEEP_NUM = s.nextInt();
    final int WOLF_NUM = s.nextInt();

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