import java.util.*;

public class Main {
    public static void main(String[] args) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main public static void main(String[] args) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } main {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    } int n = 0 n 0 m = 0; m 0 Scanner sc = new Scanner(System.in); sc new Scanner(System.in) n = sc.nextInt() n sc.nextInt() sc.nextInt sc m = sc.nextInt() m sc.nextInt() sc.nextInt sc if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        } n <= m n m {
            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) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} public class Main {
    public static void main(String[] args) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        int n = 0, m = 0;
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
        m = sc.nextInt();
        if(n <= m){
            System.out.println("unsafe");
        }else{
            System.out.println("safe");
        }
    }
}