import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    } main {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String[] s = sc.nextLine().split(" "); s sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " int hituji = Integer.parseInt(s[0]); hituji Integer.parseInt(s[0]) Integer.parseInt Integer s[0] s 0 int okami = Integer.parseInt(s[1]); okami Integer.parseInt(s[1]) Integer.parseInt Integer s[1] s 1 if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        } hituji > okami hituji okami {
            System.out.println("safe");
        } System.out.println("safe") System.out.println System.out System System.out "safe" {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    }
} Main
import java.util.*;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] s = sc.nextLine().split(" ");
        int hituji = Integer.parseInt(s[0]);
        int okami = Integer.parseInt(s[1]);
        if (hituji > okami) {
            System.out.println("safe");
        } else {
            System.out.println("unsafe");
        }
    }
}