import java.util.*;

class Main {
    private static Scanner sc;

    public static void main(final String[] args) {
        sc = new Scanner(System.in);
        int K = sc.nextInt(),A = sc.nextInt();
        if(K <= A)System.out.println("unsafe");
        else System.out.println("safe");
    }
}





 import java.util.*; util.* java class Main {
    private static Scanner sc;

    public static void main(final String[] args) {
        sc = new Scanner(System.in);
        int K = sc.nextInt(),A = sc.nextInt();
        if(K <= A)System.out.println("unsafe");
        else System.out.println("safe");
    }
} Main private static Scanner sc; sc public static void main(final String[] args) {
        sc = new Scanner(System.in);
        int K = sc.nextInt(),A = sc.nextInt();
        if(K <= A)System.out.println("unsafe");
        else System.out.println("safe");
    } main {
        sc = new Scanner(System.in);
        int K = sc.nextInt(),A = sc.nextInt();
        if(K <= A)System.out.println("unsafe");
        else System.out.println("safe");
    } sc = new Scanner(System.in) sc new Scanner(System.in) int K = sc.nextInt() K sc.nextInt() sc.nextInt sc A = sc.nextInt(); A sc.nextInt() sc.nextInt sc if(K <= A)System.out.println("unsafe");
        else System.out.println("safe"); K <= A K A 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" final String[] args args
import java.util.*;

class Main {
    private static Scanner sc;

    public static void main(final String[] args) {
        sc = new Scanner(System.in);
        int K = sc.nextInt(),A = sc.nextInt();
        if(K <= A)System.out.println("unsafe");
        else System.out.println("safe");
    }
}






